Nonmetallic Mineral Product Manufacturing (United States) — NAICS 327

A Histometrics rollup primer for a general investing audience — relevant to both public-market and private investors. NAICS (the North American Industry Classification System) is the federal standard for grouping businesses by activity; code 327 is a subsector (the three-digit level) inside Sector 31–33 (Manufacturing). This page synthesizes the five child-industry primers plus this level's own federal ground-truth statistics; it does not re-derive the leaf-level detail.

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1. Overview

NAICS 327 is the part of U.S. manufacturing that takes rock and mineral out of the ground and turns it into the physical substance of the built world — the cement in a foundation, the glass in a window, the drywall in a wall, the brick and tile on a facade, the refractory lining inside a steel furnace, the countertop in a kitchen, and the abrasives that grind and finish nearly everything else made in America. Five industries sit under the code, and almost all of them share one recipe: mine a common nonmetallic mineral, then transform it with intense heat — fire clay in a kiln, melt sand into glass, calcine limestone into cement or lime, calcine gypsum into plaster — or, in the exceptions, mold cement into concrete cold and fabricate purchased material mechanically.

For an investor, four facts frame the whole subsector:

• It is big, heavy, and local. About $165 billion of domestic factory shipments from roughly 9,100 firms running 15,300 plants and employing 412,000 people.[1] Nearly every product is heavy and cheap per pound, so it is uneconomic to ship far — which fractures the country into hundreds of regional markets and hands each plant a freight moat. The national statistics badly understate the pricing power that lives in local geography.

• It is one classification, but not one business — it is five. The children serve unrelated end-markets (housing, steelmaking, food-and-beverage packaging, semiconductors, oil-and-gas drilling), run on different demand clocks, and rarely peak together. The distinctive value of a rollup view is the contrast across them, so this page leads with that.

• The $165 billion is a 2022 peak-cycle marker, not a run-rate. This is the update the revised children force hardest. Every child that now reports a current physical read is running below its 2022 level or well below capacity: the industrial-production index for clay building materials and refractories fell to 75.17 in 2025 from 94.12 in 2022 (2017 = 100)[2]; the glass-container index fell from 109.0 to 80.6 over the same span[3]; U.S. clinker production ran 69 million tonnes against roughly 100 million tonnes of capacity[4][7]; wallboard sold about 25–26 billion square feet against 33–34 billion of capacity, and lime output slipped from 16.7 to 15.0 million tonnes since 2022[5][7]. Only inside the fifth child does a corner run tight — mineral wool, where the leading stone-wool maker expects North American demand to exceed capacity until 2028.[6] Read the Census dollars as a benchmark, and the volumes as the cycle.

• It is overwhelmingly private and foreign-owned, with a very thin public menu. Across all five children the best assets are held by private companies, private-equity (PE) firms, or the U.S. units of European, Japanese, and other foreign majors. There are exactly two listed pure-plays of any scale — a glass-container maker and a lime producer — plus two very small ones, and each carries a defect. This is the single most important thing a stock-picker needs to know before touching this subsector.

The useful mental model: 327 is a portfolio of five mineral-processing businesses — capital-heavy, energy-hungry, cyclical, freight-moated — pointed at different corners of the economy, most of which you cannot buy cleanly on a public exchange.

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2. What's inside — the five children and how they differ

The five children rhyme (all mineral-based, freight-bound, capital-intensive, cyclical) but diverge sharply on size, growth direction, ownership, and concentration. The table below is the heart of this page. Concentration is measured by CR4 (the combined revenue share of the four largest firms) and the HHI (Herfindahl-Hirschman Index, a 0–10,000 concentration score; U.S. antitrust agencies treat anything under 1,500 as "unconcentrated"). Tickers are reserved for Sections 4 and 10, per house style.

(Shares are our derived percentages of the subsector's federal receipts / employment / establishment totals in Section 3; own-concentration figures are each child's 2022 Economic Census numbers from the child primers. Glass's HHI is suppressed in the federal data at that level, as is the abrasives HHI one rung below 3279, so neither is stated.)[1][2][3][4][5][6]

Read the table this way. One child — cement and concrete (3273) — is the subsector. It is roughly half the revenue, half the jobs, and six of every ten plants, because ready-mix concrete alone is a nationwide web of thousands of small local batch plants.[4] The other four children split the remaining half: glass (3272) and other nonmetallic (3279) are the mid-sized wings at about a fifth each, while clay/refractory (3271) and lime/gypsum (3274) are the small specialists at well under a tenth apiece. The growth and the concentration, however, live in the small children: lime/gypsum (3274) is by far the most concentrated child (HHI ~1,247) and holds the sector's hottest deal-making, while the highest-margin, fastest-growing corners of the whole subsector — advanced ceramics (in 3271), specialty and solar glass (in 3272), semiconductor-polishing abrasives and code-driven mineral wool (in 3279) — are tails bolted onto otherwise mature businesses.

The heat is where the concentration is; the money is where the forming is. This is the sharpest pattern the revised children expose, and it repeats almost exactly in the subsector's two biggest members. In glass, the melting industries are small and tight while the industry that buys glass is large and loose: flat glass is ~17% of glass receipts at CR4 69.4% (HHI 1,437), while fabrication from purchased glass is ~51% of receipts and ~57% of jobs at CR4 35.7% (HHI 439) — and the reason is visible in a single number, the U.S. International Trade Commission's $0.34 per pound average net sales value for primary float producers in 2024 against $3.00 per pound for the processors who coat, temper, laminate and assemble that same glass.[3] In cement and concrete the mirror image holds: cement is ~15% of that child's receipts at CR4 51.7% (HHI 1,034), while ready-mix is ~53% at CR4 ~15% (HHI ~99).[4] Owning the furnace or the kiln buys you scarcity; owning the forming step buys you the revenue.

How the economics differ, in one paragraph. Every child obeys the same freight law and the same capacity-utilization logic (heavy plants earn most when run flat-out and hot), but they sit at very different points on the capital and concentration spectrum. Cement is the extreme heavy-industry end — enormous kilns, few plants, tens of millions of revenue each, a handful of global owners. Ready-mix concrete is the opposite — thousands of modest, commodity, low-margin batch plants. Lime and gypsum are the most concentrated — a few automated calcining plants per region behind steep permitting barriers, with lime and gypsum individually at CR4 82.6% and 84.1%. Glass splits into furnace "melters" with punishing operating leverage and a fabricator that earns a value-added spread on purchased glass. And other nonmetallic ranges from capital-heavy mineral-wool furnaces (HHI 1,106) down to thousands of tiny, labor-heavy cut-stone shops (HHI 52).[2][3][4][5][6] The one thread that binds all five for an investor: the real money is made by owning freight-protected regional assets, and most of those assets are private.

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3. How big it is (the rollup figures)

These are our ingested ground-truth federal statistics for NAICS 327 (U.S. Census Bureau). They are the clean sum of the five children on every physical measure. (EC = Economic Census, the every-five-years benchmark; CBP = County Business Patterns, the annual establishment count.)

Concentration — nationally near-atomistic (2022 Economic Census): the largest 4 firms make just 9.3% of shipments, the top 8 16.9%, the top 20 30.6%, and the top 50 45.3%; the subsector HHI is just 61.[1]

The children reconcile cleanly into the subsector — with one telling exception. Employment sums exactly (35,582 + 87,874 + 189,833 + 15,543 + 83,488 = 412,320) and so do establishments (1,036 + 1,541 + 9,134 + 265 + 3,341 = 15,317); receipts land within rounding of $164.79B. The one number that does not simply add up is the firm count: the five children list ~9,197 firms, but the subsector shows 9,104 — about 93 fewer.[1][2][3][4][5][6] That gap is companies that operate in more than one of these five industries — counted once in each child yet only once at the subsector level — and it is a direct, if rough, measure of the cross-mineral conglomerates that recur across this whole page: Saint-Gobain (glass, gypsum, abrasives, insulation, refractories), CRH (cement, concrete, construction materials), Martin Marietta (aggregates and, on closing, lime), Minerals Technologies (refractories and specialty minerals), and Eagle Materials (cement and gypsum). The same effect nests one level down inside individual children, which is why no rung of this hierarchy can be read as a single market.[3][4][5]

The concentration mirage — why the subsector looks hyper-competitive while its parts are oligopolies. A CR4 of 9.3% and an HHI of 61 read as one of the least concentrated corners of American manufacturing — and that is almost entirely misleading. Two forces reconcile it. First, it is a pooling artifact, and the revised children now make that argument independently at four different levels: 3271's HHI of 213 is lower than either of its two children (954.7 and 256); 3274's 1,246.8 is far below both of its children (1,931 and 1,934.6); 3279's 159.2 is below its own larger child (172.3); and inside 3273 the pipe/brick/block CR4 of 30.8% sits below both of its children (35.5% block, 47.6% pipe).[2][3][4][5][6] Note the tell at the top: the subsector's HHI (61) is lower than every child's — impossible for a genuinely more-competitive market, and pure aggregation math, because the leaders in one product market are different firms from the leaders in another. Second, and more important, the national figures ignore geography. Because freight carves the country into regional markets, a typical metro is served by only two or three cement plants, a handful of ready-mix or brick plants, one or two lime kilns, or a single stucco plant. Local concentration is far higher than any national number here — the true market power lives in geography and in the genuinely concentrated sub-industries (lime and gypsum near HHI 1,930 each; glass containers and flat glass with top-four shares near 88% and 69%; mineral wool at HHI 1,106; cement at 1,034), not in the CR4. Read the subsector HHI as a reminder that these are five separate competitive arenas glued together, not one competitive market.

Undercount and boundary caveats. Coverage of production is generally good here — these are large, capital-intensive, easy-to-survey plants, not cash or gig operators, and no value in the table above is suppressed. The distortions run in specific directions and all matter to investors:

• The mined rock sits in a different code. Quarrying the sand, gravel, limestone, gypsum rock, dimension stone (212311), industrial and frac sand (212322), and abrasive grit that feed these plants is classified as mining (NAICS 212), not manufacturing — so 327 captures the processing and forming value-add, not the raw material beneath it. The distortion is largest in 3279's miscellaneous bin, where raw frac sand is roughly 80%+ of all proppant tonnage and none of it is counted here. The true "minerals economy" is far larger than $165B.[4][6]
• Imports are large for the light goods, and the number is factory-gate. These are U.S. production figures. Imports supplied 72.4% of U.S. ceramic-tile consumption by volume in 2025[2][23]; China alone supplied about 96% of U.S. crude fused-aluminum-oxide and 97% of crude silicon-carbide imports in 2025[6][7]; U.S. cement was 21% net-import-reliant and crude gypsum about 15%, while lime is under 1%.[4][5][7] Private "market" estimates for wallboard, plumbing fixtures, abrasives, countertops or flat glass run far above these Census figures because they bundle in imports, distribution margin, and installation — but a few run lower because they are narrower, so always check the scope before comparing.[2][3][5][6]
• The artisan and captive tails are partly invisible. Individual studio potters and one-person cut-stone and monument shops file as nonemployers and never appear in the employer counts — a headcount undercount concentrated at the craft end of 3271 and 3279, and essentially absent in abrasives, which is factory manufacturing with no sole-proprietor tail.[2][6] A slice of lime is made captively and buried in other industries' statistics: 8 of the 24 lime companies the U.S. Geological Survey tracks produce strictly for internal use.[5][7]
• The real "undercount" for a public investor is that most of this value never trades. The fragmented ready-mix, precast, cut-stone, fabrication, and regional-plant tails are thousands of family firms whose economics are invisible in public filings.[3][4][6]

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4. The investable universe — where value concentrates across the children

The defining fact for a public-market investor: there is no clean, U.S.-listed pure-play on this subsector, and only two listed pure-plays of any scale inside it — a glass-container maker and a lime producer — supplemented by two much smaller ones, in precast and in ground minerals. Everything else reaches public markets bundled inside diversified building-materials, industrial, or specialty-materials companies, where any one child is a slice — often the lowest-margin, most cyclical slice — of a broader portfolio. Where the listed money sits differs sharply by child, and two of the five menus changed materially in the past year. (Tickers appear here for the first time.)

• Cement & concrete (3273) — the biggest child, the deepest indirect menu, and the most reshuffled. No clean pure-play spans it; CRH plc (NYSE/LSE: CRH) is the single cleanest listed proxy because it is the only listed name touching all four of its sub-industries. Cement-centric integrated exposure comes via Amrize (NYSE/SIX: AMRZ, Holcim's 2025 North America spin-off, ~$11.8B of 2025 revenue), Cemex (NYSE: CX), Eagle Materials (NYSE: EXP, ~6% of U.S. clinker capacity), and Titan America (NYSE: TTAM). Commercial Metals (NYSE: CMC) is a new entrant of scale, having bought Concrete Pipe & Precast ($675M) and Foley Products ($1.84B) in 2025; NWPX Infrastructure (NASDAQ: NWPX) is the most focused listed touch on the pipe side and L.B. Foster (NASDAQ: FSTR) a partial precast exposure; Smith-Midland (NASDAQ: SMID) is the lone tiny precast pure-play. Two aggregates names have narrowed: Vulcan Materials (NYSE: VMC) sold its California ready-mix to CalPortland in June 2026, and Martin Marietta (NYSE: MLM) exited ready-mix altogether in February 2026 — MLM is no longer a route into this child at all, a direct correction to what this page previously said. Knife River (NYSE: KNF) still carries ready-mix; foreign majors reach U.S. investors via ADRs (Heidelberg HDELY, Buzzi BZZUY). The private analog to CRH is Quikrete, which now spans all four sub-industries after taking Summit Materials private (~$11.5B, closed February 2025), owning the Rinker/Forterra pipe platform, and picking up Martin Marietta's Texas cement and ready-mix.[4]
• Glass (3272) — one clean pure-play, otherwise diluted. O-I Glass (NYSE: OI), the world's largest glass-container maker (~$6.3B of FY2025 segment sales), is one of the subsector's two pure-plays of scale — but the revised child adds a caution: its Americas rebound to $549 million of operating profit sat inside a $129 million net loss for 2025 after restructuring charges and interest on roughly $5 billion of debt. Corning (NYSE: GLW) offers diluted exposure through Specialty Materials ($2.2B) and Life Sciences ($972M) inside a ~$15.6B optical-fiber and AI business; Apogee (NASDAQ: APOG) is a partial fabrication play (Architectural Glass $283.7M of FY2026 sales) and Gentex (NASDAQ: GNTX) an automotive-mirror and dimmable-glass angle; vehicle glass runs through D'Ieteren (Brussels: DIE), controlling owner of Belron/Safelite. Flat glass has no U.S. pure-play (Guardian/Koch and Cardinal are private; Vitro, NSG, AGC, Saint-Gobain are foreign), and fabrication — the largest slice — is overwhelmingly private and PE-owned.[3]
• Lime & gypsum (3274) — one lime pure-play, no gypsum pure-play. United States Lime & Minerals (Nasdaq: USLM) is the sole listed pure-play — $372.7 million of 2025 revenue at a 48.9% gross and 42.4% operating margin, debt-free and high-margin, but closely held and single-region. The diversified lime way in is Martin Marietta (NYSE: MLM), which agreed in June 2026 to buy Lhoist North America for $13.5 billion to become the largest U.S. lime producer, at about 15 times 2025 adjusted EBITDA including expected synergies, with closing expected in the second half of 2026.[5][17] Gypsum has no pure-play at all — the U.S. leader USG is owned by Germany's Knauf; the closest listed name is Eagle Materials (NYSE: EXP), whose wallboard segment earned $286.8 million on $764.5 million of revenue in fiscal 2026 inside a ~$2.3 billion, majority-cement company, plus Saint-Gobain (Euronext Paris: SGO; U.S. OTC: CODYY) for its CertainTeed unit.[5]
• Other nonmetallic (3279) — thin, indirect, clustered, but deeper than this page previously allowed. No leader is a pure-play, but Oil-Dri (NYSE: ODC, ~$486M of FY2025 revenue at a 29.5% gross margin) is the nearest U.S.-listed pure-play anywhere in the child — small, and not the industry leader. The cleanest listed themes: Owens Corning (NYSE: OC, $3.7B of 2025 insulation sales at a 23% EBITDA margin) and Rockwool (Nasdaq Copenhagen: ROCK-B, €3.88B group revenue, €737M in North America) for mineral wool, with TopBuild (NYSE: BLD, $4.3B) and Installed Building Products (NYSE: IBP) giving the same demand one layer downstream without furnace and energy risk; Minerals Technologies (NYSE: MTX, ~$2.07B) and Imerys (Euronext Paris: NK) for specialty minerals; 3M (Abrasives division $1.34B of 2025 sales inside a $24.9B company, and it completed the sale of its Precision Grinding & Finishing business in April 2026) and Saint-Gobain for abrasives; and the fastest-growing corner of the whole subsector — semiconductor polishing — via Fujimi and Entegris. Stressed or hybrid names include Caesarstone (Nasdaq: CSTE, shrunk to ~$397M of 2025 revenue) in engineered stone, Matthews International (Nasdaq: MATW), and Atlas Energy Solutions (NYSE: AESI) and Smart Sand (Nasdaq: SND) in frac sand.[6]
• Clay product & refractory (3271) — no manufacturing pure-play, foreign or private only. The one direct U.S. listing that has surfaced, FGI Industries (NASDAQ: FGI, ~$130.5M of revenue), is primarily an importer and distributor of sanitaryware rather than a domestic ceramic manufacturer, and carries heavy concentration risk. Otherwise: sanitaryware through Japan's LIXIL and TOTO (ADR TOTDY), Switzerland's Geberit, and Taiwan's Globe Union; technical ceramics through Kyocera (NYSE: KYO); refractories through RHI Magnesita and Vesuvius (London) plus PE-owned Calderys/HarbisonWalker; brick through Wienerberger (Vienna) and now Soul Patts (ASX: SOL), which took Glen-Gery's eight U.S. plants in the September 2025 Brickworks merger — an ownership change since this page last listed Brickworks itself; tile through Mohawk Industries (NYSE: MHK, via Dal-Tile, Global Ceramic $4.289B at ~6.2% operating margin). Crown-jewel U.S. assets (Kohler, CoorsTek, Acme Brick inside Berkshire Hathaway) are private or immaterial to their owners.[2]

The through-line across all five children: to own 327 through public markets you buy a diversified building-materials, industrial, or specialty-materials compounder where one of these industries is a slice — CRH, Saint-Gobain, Martin Marietta, Owens Corning, Minerals Technologies, Eagle Materials, Commercial Metals — or a foreign-listed leader, or one of the four pure-plays, each with a defect: O-I loss-making at the bottom line in 2025, USLM closely held and single-region, Smith-Midland a thinly traded micro-cap that disclosed material internal-control weaknesses for FY2025, and Oil-Dri small and not a leader. Concentrated exposure to any single child is fundamentally a private-market proposition. Full company tables, revenues, and owner rosters are in the five child primers.

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5. How the money works

Owners across all five children make money the same basic way: convert cheap, bulk mineral inputs into a heavier, freight-protected product, and sell it inside a tight radius before shipping costs erode the margin. The relevant economics are those of capacity-utilization, input-cost, and freight-bound manufacturing — not the regulated rate base of a utility, the funds-from-operations of a REIT, or the all-in sustaining cost of a miner. The shared levers:

• The weight-to-value moat, and its exceptions. Cement moves ~150–300 miles economically (Cemex sells most U.S. cement within about 200 miles of a plant); wet ready-mix only ~20–30 miles, bounded by the ASTM C94 limit of 90 minutes and 300 drum revolutions, with roughly 95% of output moving under 100 miles; block ~150–200 and pipe ~150–250; commodity precast under ~150. Freight is a quarter of the delivered price in lime, and Eagle books $51.00 per thousand square feet of wallboard freight against $226.08 of average net price. Mineral wool is "mostly air," which is why foreign leaders build U.S. plants instead of exporting.[4][5][6] The exceptions matter: abrasives, ceramic tile, tableware, and specialty glass have enough value per pound to trade globally, so their competitive pressure comes from imports and tariffs rather than local freight.[2][3][6]
• Capacity utilization governs margins — but not always through the same mechanism. These are fixed-cost, capital-heavy assets that run best flat-out and, for the melters and kilns, hot and continuous (a glass furnace runs a 10–15-year "campaign"; an idle kiln is very expensive). The live evidence across the children is unusually clear this cycle: CRH averaged 72% kiln utilization in 2025; flat-glass utilization fell from 92.9% (2022) to 84.4% (2024) as producer operating margin went from 10.8% (2024) to 6.4% in the first half of 2025; Wienerberger's North American EBITDA margin dropped from 24.0% to 18.8% on an 8% volume decline despite a 1% price increase.[2][3][4] One correction the gypsum child forces on the blanket version of this rule: Eagle discloses that fixed costs are less than 20% of overall wallboard cost, so slack utilization there moves realized price — regional pricing discipline — far more than it moves unit cost.[5] Utilization matters everywhere; whether it works through absorption or through price depends on the child.
• Energy is the swing cost — and the measurements genuinely differ. High-temperature firing, melting, and calcining is the decisive variable input across the fired children. Energy runs roughly 30% of brick manufacturing cost and 25%+ of lime production cost (about 2.77 million Btu per ton), but only 8–10% of wallboard cost, where paper facing is about a third.[2][5] In glass the two published measures disagree: USITC questionnaire data put purchased energy at 6.6% of net sales for flat-glass producers in 2024, while market-research figures reach ~14% of production cost across U.S. glassmaking — a difference of denominator and scope rather than a factual dispute, so read the lower as a measured floor for large float producers and the higher as a ceiling for more energy-intense melting.[3] Natural gas dominates the fuel mix throughout; recycled inputs blunt it (each additional 10 percentage points of cullet cuts glass melting energy about 2–3%; supplementary materials cut cement clinker content).[3][4]
• Input-cost pass-through, with a lag. Cement is the largest raw input to the three downstream concrete children — the U.S. Geological Survey puts 70–75% of 2025 U.S. cement shipments into ready-mix and about 11% into concrete products, and cement is roughly a quarter of ready-mix revenue per cubic yard.[4][7] Steel rebar feeds pipe and precast; paper feeds gypsum board; abrasive material costs rose an estimated 15–25% in 2025 on trade-policy changes.[5][6] Producers pass spikes through on new quotes — but the lag squeezes margins in the meantime, worst where work is bid months before it is produced.
• Product mix and vertical integration set the top of the margin range. In every child the premium grade beats the commodity one — advanced ceramics over tableware, coated/low-E and specialty glass over commodity flat glass, superabrasives and engineered ceramic grain over sandpaper, fire-rated wallboard over standard. The spread inside a single mineral can be enormous: diatomite runs from roughly $10 per tonne as lightweight aggregate to more than $1,000 per tonne in specialty applications.[6] And the best-returning operators own the whole chain (the cement kiln and the aggregate pit and the ready-mix plant), capturing margin at every stage.[2][3][4][6]

The margin ladder across the children — read the ordering, not the levels. The revised children now support a rough cross-subsector ranking, with a large caveat: these are different margin definitions (gross, operating, EBITDA, segment) over different scopes and periods, and several are global listed proxies rather than code averages. At the top sit the concentrated calcining businesses and the specification-led brands — USLM at ~42% operating, Eagle's wallboard segment at ~38% and its cement segment at 27% operating, Geberit at 29.4% EBITDA, Oil-Dri at 29.5% gross. In the middle sit specialty minerals and insulation — Minerals Technologies ~25%, Owens Corning insulation ~23% EBITDA, Rockwool ~21.3%, CRH's Americas Building Solutions 20.7% adjusted EBITDA, NWPX's precast segment 20.8% gross. At the bottom sit the pressured melters and the fabricators — Wienerberger North America 18.8%, Caesarstone 18.4% gross, Apogee's architectural glass at 8.7% in the most recent quarter after 22.2% two years earlier, flat-glass producers at 6.4% operating.[2][3][4][5][6] And beneath all of it sits the subsector's largest single industry: ready-mix concrete earned about 9% pretax in a strong year (2023) but averaged only $3.31 per cubic yard of pretax profit and a 4.3% pretax return on assets across fifteen years of trade-association survey history — the most important number in the whole subsector, and the reason commodity ready-mix is the thinnest business under this code.[4][9]

The two genuine structural outliers: the glass fabricator (327215) and the cut-stone shop (in 3279) buy finished material and earn a value-added spread rather than melting or firing raw mineral — labor-heavy, lower-capital, thinner per-job margins, with yield mattering more than in melting because a defect after coating or lamination destroys the purchased material plus all the labor already in it.[3][6]

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6. What drives demand

Because the subsector fuses five mineral processes to serve unrelated markets, it rides several demand curves at once — which is exactly why no single macro number captures it:

• Construction — the master driver, with a correction on which construction. Residential, non-residential, and public building pulls the great majority of this subsector, and 327 amplifies the building cycle because it is interest-rate-sensitive and operating-leveraged. In 2025 that meant private construction spending fell 2.9% to $1.6475 trillion while public rose 3.6% to $516.8 billion.[4][21] The biggest policy tailwind remains the Infrastructure Investment and Jobs Act (IIJA, 2021) — roughly $1.2 trillion, about $500 billion for roads and bridges and $55 billion for water, with only ~40% of the roads-and-bridges money spent as of late 2025.[4][20] But the children now correct a common framing: for the subsector's largest child, public work is not the biggest demand source. The ready-mix end-market mix runs 44% commercial, 31% residential, 9% public works, 11% roads, 5% parking — all public work at roughly 20%, well behind private commercial building. Infrastructure is the most policy-durable and least rate-sensitive channel, not the largest one.[4][9]
• Heavy industry, above all steel. Steelmaking drives both refractories (furnace linings, in 3271) and lime (as a flux, in 3274). The children disagree on the refractory share and say so: the World Refractories Association puts steel at ~70% of demand while IBISWorld's read is nearer two-thirds.[2] Lime's last detailed federal breakdown (2021) shows metallurgical uses at 6.25 million tonnes, of which 5.25 million went to iron and steel.[5] Crucially, furnace linings wear out and must be replaced regardless of new construction, giving refractories and lime a steadier floor than the purely building-driven children.[2][5]
• Food-and-beverage packaging. Glass containers (in 3272) rise and fall with bottled-beverage and food demand — the mix is now explicit at 42.2% beer, 26.0% food, 9.7% wine and 5.0% ready-to-drink — and they are the subsector's most defensive leg on volume (in 2007–09 non-container glass shipments fell about 20% against about 4% for containers), even as their long-run direction is downward under can and plastic substitution.[3]
• Technology — the fastest-growing wedge. Semiconductors, medical devices, EVs, and telecom drive the highest-margin tails: advanced ceramics (3271, a global market of roughly $12.86B in 2025 rising to ~$17.24B by 2030, ~6% CAGR — global and broader than the code, so directional only), specialty glass (3272), and semiconductor-polishing abrasives (CMP, 3279 — visible in Fujimi's 22% sales growth).[2][3][6][24] The AI-driven data-center buildout is the standout structural growth story: U.S. data-center construction spending rose roughly 35% to about $42 billion in 2025 and drove some 42% of national non-residential building growth, lifting demand for precast and ready-mix, insulation and construction chemicals, and CMP abrasives at once.[4][6][22]
• Building-energy and fire codes. Each tightening raises required content per building — the structural tailwind for mineral wool (3279) and for safety and energy-performance glass (3272). Behind it sits a long retrofit runway: the Department of Energy puts opaque building envelopes at 28% of building energy use and windows at about 10%, and expects nearly 93% of today's homes still to exist in 2050.[3][6]
• Solar — real, but conditional. NSG converted its Rossford, Ohio float line to coated transparent-conductive-oxide glass for First Solar starting March 2025, and Vitro has proposed a new patterned low-iron solar furnace in Texas. The caveat the revised child adds and this page previously glossed: solar is not automatic growth for every float line — chemistry, iron content, texture, coatings, and customer qualification determine whether a plant can serve it at all.[3]
• Oil-and-gas drilling. Barite weighting agent (more than 90% of which goes into drilling mud) and engineered proppants (in 3279) rise and fall with rig counts — the most volatile demand leg in the whole subsector, and one that touches none of the others.[6]
• Coal-plant retirement — the subsector's most under-appreciated cross-child force, and it is not a hedge. The revised children make explicit something no earlier version of this page said: the shrinking U.S. coal fleet pushes on three children at once, all in the same direction. It erodes lime demand for flue-gas desulfurization, the second-largest environmental use; it shrinks the synthetic gypsum that was about 34% of 2024 U.S. gypsum supply, forcing wallboard makers toward mined and imported rock; and it tightens the conventional fly-ash supply that cement producers use to cut clinker content. Retirements slowed to 2.6 gigawatts in 2025, but the direction of travel is one way.[4][5][18]

The upshot is partial buffering, with one exception: a recession that chills private building hits ready-mix, brick, glass, and gypsum, but does not vanish public infrastructure budgets, furnace-lining replacement, or environmental lime demand the same way. A holder of the whole subsector is diversified across cycles that rarely peak together — except on coal, where a single structural shift works against several children simultaneously.

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7. Regulation

Regulation across 327 concerns emissions and decarbonization, worker safety, trade, and product/building standards — not rate-of-return regulation or reserve accounting. Four threads run through the subsector:

• Air emissions and carbon — the defining long-term issue. Kilns and furnaces are combustion point-sources under the Clean Air Act, governed by EPA NESHAP/MACT standards (National Emission Standards for Hazardous Air Pollutants / Maximum Achievable Control Technology) for Portland cement, brick and structural clay products, clay ceramics, refractory products, lime, and glass manufacturing.[13] Carbon is the forward risk, and it starts at cement, which causes an outsized share of global CO₂ (commonly cited near 7–8%) because most of its emissions are chemical — the Department of Energy attributes 58% of 2015 U.S. cement-industry CO₂ to calcination, the release of carbon dioxide when limestone is heated, which is why fuel switching alone cannot decarbonize conventional clinker.[4][14] Lime carries the same unavoidable process CO₂ (~0.75–0.79 ton per ton, about two-thirds of a plant's emissions); glass adds its own, with 22 U.S. flat-glass plants emitting 2.95 million tonnes of CO₂-equivalent in 2019.[3][5] Costs are being priced in now: the July 2024 tightening of the lime NESHAP added limits on hydrogen chloride, mercury, organic HAPs and dioxins at an EPA-estimated $484 million of control capital and ~$167 million of annual cost, with a modeled 5.5% price increase and 1.4% output decline — though EPA announced in March 2025 that it would reconsider several air rules, so the trajectory carries policy uncertainty.[5] Industry responses include Portland-Limestone Cement (Type IL, approved in all 50 states and about 10% less CO₂ per ton, with blended cements roughly 63% of first-nine-month 2025 shipments), supplementary materials, carbon capture backed by federal 45Q credits, and, in glass, a costly shift toward electric/hybrid melting.[3][4][13] Demand-side carbon rules are now real money too: EPA's low-embodied-carbon label program (August 2024, $250 million for environmental product declaration reporting and $100 million for the label) and a Federal Highway Administration low-carbon materials program authorized at up to $2 billion reward the cleanest producers directly.[4][6]
• Respirable crystalline silica — cross-cutting, but with one clear exception. Cutting, grinding, and handling clay, concrete, stone, and abrasives releases fine silica dust that causes silicosis, an incurable lung disease. OSHA sets a permissible exposure limit of 50 micrograms per cubic meter over an 8-hour shift with a 25 µg/m³ action level, and MSHA matched it for mines in 2024.[15] The acute front is the engineered-stone silicosis crisis (in 3279): quartz slab can be >90% crystalline silica, and California — 542 confirmed cases and 29 deaths as of April 2026 — has banned dry-cutting under the STOP Act (SB 20, in full effect January 1, 2026) and moved toward prohibiting fabrication of engineered stone above 1% silica, echoing Australia's July 2024 ban.[6][16] The correction the revised child supplies: mineral wool sits outside the silica story entirely — its hazard is fiber irritation, and glass, rock and slag wool are classified IARC Group 3, "not classifiable as to carcinogenicity" — so roughly a quarter of 3279's dollars are unaffected.[6] A second-order effect is worth noting: the silica rule pushed many blasting operators off silica sand and onto alternative media carrying heavy-metal hazards of their own, moving the risk rather than removing it.[6]
• Trade remedies — active in every child, and now correctly dated. This page previously placed the float-glass duties in February 2026; the revised child sharpens the sequence. The USITC made its final injury determinations in March 2026; Commerce issued an antidumping order on Chinese float glass (margins of roughly 247–312%, published in the Federal Register in April 2026) and countervailing-duty orders on both China and Malaysia, while the Malaysian antidumping case was terminated on negligibility grounds.[3][11] Critically, that is a tailwind for domestic float and solar reshoring and, inside the same child, a substrate-cost headwind for independent fabricators who buy that glass — the clearest case in the subsector of one remedy cutting two ways at once.[3] Elsewhere: new AD/CVD orders on Chinese sol-gel alumina ceramic abrasive grain after a September 2025 injury finding; quartz surface product orders continued January 15, 2026 (China at roughly 265–340%, India and Türkiye at roughly 3.8–80.8%); antidumping duties above 350% on Chinese ceramic tile plus Section 301 tariffs of 25% on most affected Chinese ceramics and abrasives; and 25% 2025 tariffs on Canadian and Mexican cement, which raise the downstream concrete children's largest input cost directly.[2][4][6][12]
• Product and building standards, and procurement. ASTM/AASHTO and TMS standards license concrete, pipe, and block into projects, and NPCA/PCI plant certification is often a bidding precondition — losing an approved-product listing can disqualify a producer outright.[4] Safety-glazing (16 CFR Part 1201, IBC §2406) and energy codes raise glass and insulation content per building; ASTM fire tests and the FTC R-value Rule govern insulation labeling; water-efficiency rules favor high-efficiency toilets (WaterSense at 1.28 gpf against the 1.6 gpf federal standard, with the Version 2.0 effective date paused); hurricane and fire codes favor masonry and mineral wool.[2][3][6] Build America, Buy America rules favor domestic producers on federally funded work, though the mechanics are more nuanced than industry marketing suggests: FHWA treats precast concrete as a manufactured product while cement, cementitious materials and aggregates fall outside the statutory definition of "construction materials," and the general manufactured-products waiver ended March 20, 2025.[4] One correction on the gypsum side: EPA's Coal Combustion Residuals rules exclude encapsulated beneficial reuse such as wallboard from federal disposal regulation, so gypsum's supply risk reaches producers through utility compliance costs and plant closures, not through a rule aimed at panel makers.[5] Several of these regulations create demand as much as they constrain it.

Because local markets are concentrated, antitrust is unusually live in the downstream and most-concentrated children — ready-mix has drawn repeated Department of Justice price-fixing enforcement (Argos USA paid a $20 million criminal penalty and two executives were convicted), the California Attorney General required plant divestitures as a condition of CalPortland's 2026 purchase of Vulcan's California assets, pipe deals have required DOJ-mandated divestitures, and gypsum's high concentration produced the 2011–12 drywall price-fixing litigation, in which USG settled for roughly $48 million.[4][5]

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8. Consolidation

The subsector's defining structural feature is national fragmentation slowly being rolled up, atop tight local and genuinely concentrated national markets — but the five children sit at very different points on that curve, and they consolidate along different axes:

• Cement & concrete (3273) — cement is already a foreign-owned oligopoly, with the top five producers at roughly 57% of U.S. output after a decade of Lafarge/Holcim, CRH/Ash Grove and Heidelberg/Lehigh mergers, while ready-mix, block, and precast are fragmented tails rolled up by public CRH and private Quikrete (which took Summit private, ~$11.5B, closed February 2025) and by PE platforms. Two things are new: Commercial Metals arrived as a scaled strategic buyer, paying $675 million (9.5× estimated EBITDA) for Concrete Pipe & Precast and $1.84 billion (10.3×) for Foley Products in 2025 — the clearest public price marks in the subsector for what a plant portfolio actually trades at — and the aggregates majors rotated out, with Martin Marietta exiting ready-mix in February 2026 and Vulcan selling its California ready-mix in June 2026. The sobering lesson the child now quantifies: twenty years of continuous precast roll-up moved that industry's CR4 only from 15.4% to 16.3%. Roll-ups here buy local density, not national share.[4]
• Lime & gypsum (3274) — the most concentrated child, consolidated by large deals by deep-pocketed, mostly foreign or diversified owners: gypsum by Knauf's ~$7B buy of USG (2019) and Saint-Gobain/Continental (~$1.4B, 2020); lime by Martin Marietta's $13.5 billion agreement to buy Lhoist North America (June 2026) at about 15 times 2025 adjusted EBITDA including synergies, bringing more than 2 billion tons of reserves — a national-scale strategic multiple that should not be read across to smaller regional plants, and a signal that cash-rich aggregates majors now value lime's margins at a premium.[5][17] The gypsum distribution layer consolidated too, and out of reach: GMS now sits inside Home Depot's SRS and Foundation Building Materials inside Lowe's after an $8.8 billion deal in October 2025, closing what had been a back-door listed route into the child.[5]
• Glass (3272) — flat glass and containers are consolidated oligopolies (top-four shares near 69% and 88%), but containers are now consolidating through balance sheets and furnace closures rather than acquisitions: O-I is mid-way through a program targeting ~$750 million of cost reduction and closing roughly 13% of capacity; Ardagh's 2025 recapitalization wrote off or swapped about $4.3 billion of debt in an exchange S&P labelled a selective default; Anchor Glass cut debt by more than 60%. Glassware has consolidated through distress to the point of fragility — employment down 72.9% since 2000, with three of roughly ten surviving U.S. glass-tableware furnaces on a single Lancaster, Ohio site. Fabrication is fragmenting-then-rolling-up from the bottom via PE (KPS's buyout of Oldcastle BuildingEnvelope at a $3.8 billion enterprise value, roughly 11× 2020 EBITDA) and float-maker vertical integration.[3]
• Other nonmetallic (3279) — a top-heavy abrasives pyramid (CR4 50.5%, top 50 ~87.4%) atop a fragmented ~240-firm base ripe for PE roll-ups, with 3M's retreat now complete after it closed the sale of its Precision Grinding & Finishing business in April 2026. The "all other" bin holds four different stories: atomized cut stone (HHI 52, the textbook roll-up target), PE-bought ground minerals (Apollo took U.S. Silica private for ~$1.85 billion in July 2024), oligopolistic mineral wool consolidating by capacity build-out rather than deals, and a brutal proppant shakeout alongside a packaged-concrete megadeal.[6]
• Clay & refractory (3271) — globalized rather than domestically rolled up (American Standard inside LIXIL; refractories consolidating fast under RHI Magnesita, which added €184 million of North American revenue with Resco in 2025, and PE-owned Calderys/HarbisonWalker under Platinum Equity), with brick ownership changing hands again in September 2025 when the Brickworks–Soul Patts merger moved Glen-Gery's eight U.S. plants under a diversified Australian holding company, and notable premium-end reshoring (TOTO's new $224M Georgia plant, lifting U.S. luxury-toilet capacity ~150%).[2]

The recurring theme: a short list of cross-mineral conglomerates — Saint-Gobain, CRH, Martin Marietta, Minerals Technologies, Eagle Materials, plus private Quikrete — stitch these markets together and account for the ~93-firm reconciliation gap in Section 3. Acquirers ignore the code boundaries entirely: they buy capabilities while the Census counts markets, which is why the subsector's headline HHI of 61 understates real market power in every child. The clearest illustration is Martin Marietta, which in eighteen months exited one child (ready-mix) and, on closing, will lead another (lime).

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9. Risks

• Construction cyclicality (the dominant risk). With cement/concrete alone about half the subsector, and construction pulling most of the other children too, 327 is heavily geared to the building cycle; high fixed costs and operating leverage mean volume downturns hit utilization and margins hard, especially in rate-sensitive residential work. The reference case is ready-mix's 2005–2010 collapse — from 458.3 million cubic yards to 257.4 million, a 44% fall that took roughly fifteen years to recover, over a fifteen-year stretch that averaged just $3.31 per yard of pretax profit and a 4.3% pretax return on assets. The cushions are refractory and lime replacement demand, public infrastructure budgets, and code-driven content growth.[2][4][5][6][9]
• Energy shocks. Continuous high-temperature firing, melting, and calcining make margins across the fired children acutely sensitive to natural-gas prices — most so where energy is a quarter to a third of cost (brick, lime), least so in wallboard.[2][3][4][5]
• Decarbonization capex and carbon transition. The hardest-to-abate emissions profile in materials sits at the cement base — 58% of U.S. cement CO₂ comes from calcination chemistry, not fuel — and runs downstream into every load of concrete; lime carries the same process CO₂ and has already been handed a ~$484 million industry control-capital bill; glass and brick firing add to it. Capture technology is capital-heavy and unproven at scale, and fly-ash supply tightens as coal plants retire.[4][5][14]
• Silica regulation and litigation — a swing factor for the stone-heavy corners. A spreading engineered-stone ban would gut a high-growth product line in 3279 (Caesarstone has already booked a $50 million silicosis provision); tighter enforcement raises compliance costs across concrete cutting, ceramics, and abrasives; talc-asbestos suits remain a bankruptcy-scale risk in specialty minerals, where Minerals Technologies booked a further $215 million provision in 2025. Mineral wool is the notable exemption.[6][16]
• Import and input concentration, and trade-policy whiplash. The light goods — tile, tableware, glassware, quartz slab, crude gypsum — stay structurally exposed to low-cost imports and fast-moving tariff policy. The sharper risk the revised children expose is upstream input concentration: China supplies roughly 96% of U.S. crude fused-alumina and 97% of crude silicon-carbide imports and more than 60% of globally traded refractory raw materials, so two children depend on a single country for the grit and grain they process. Tariffs cut both ways — protecting some domestic makers while inflating others' inputs, most visibly in glass, where the same duty helps the melter and hurts the fabricator.[2][3][6][7][11][12]
• Coal-fleet retirement. The one structural force that pushes on several children at once and in the same direction: lime's flue-gas demand, gypsum's synthetic feedstock, and cement's conventional fly-ash supply all shrink together.[4][5][18]
• Substitution — a different threat per child. Concrete and block face wood/steel framing, tilt-up, insulated concrete forms and mass timber; pipe loses ground to plastic (Advanced Drainage Systems names Quikrete, Forterra and Oldcastle as its principal concrete-pipe competitors); glass containers lose to aluminum cans and plastic; clay brick faces stucco, vinyl and fast-rising fiber cement against its ~18.5% cladding share; mineral wool competes with foam plastics; ceramic proppant competes with untreated sand. Product-specific, but pervasive.[2][3][4][6]
• Overcapacity and lumpy additions. Slack is already visible at the cement base (69 Mt of clinker against ~100 Mt of capacity), in wallboard (~25–26 BSF sold against ~33–34 BSF of capacity), and in flat glass; in mineral wool, several large indivisible lines commission in 2027–2028 and will decide whether today's tightness converts to margin or to price competition.[3][4][5][6][7]
• Customer and channel concentration — a risk earlier versions of this page missed. Three customers were roughly 64% of Eagle's fiscal-2026 wallboard segment sales; drywall distribution now sits inside Home Depot and Lowe's; big-box order flow pressures cut-stone fabricator pricing; and the subsector's one direct U.S. clay-products listing draws 66% of sales from ten customers.[2][5][6]
• Public-market thinness — the defining investor risk. With only four listed pure-plays in the entire subsector — two of scale and two small, each with a defect — every other route buries the thesis inside a diversified major (with currency and multi-segment noise) or a private/PE structure that never trades. The best assets are the least accessible.[1][3][4][5][6]

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10. How to invest, and the outlook

Choose the child (or theme) first, then the vehicle — because there is no clean way to buy "327."

• For broad building-materials exposure (mostly cement & concrete, 3273): the diversified majors are the route — CRH (the single cleanest listed proxy, the only name touching the biggest child end-to-end), plus Amrize (AMRZ), Cemex (CX), focused domestic Eagle Materials (EXP) and Titan America (TTAM), aggregates-led Vulcan (VMC) and Knife River (KNF), newly scaled precast-and-pipe via Commercial Metals (CMC), focused touches in NWPX Infrastructure (NWPX) and L.B. Foster (FSTR), and foreign cement ADRs. Note the correction: Martin Marietta (MLM) is no longer a route into this child after its February 2026 ready-mix exit. These trade on EV/EBITDA (enterprise value to earnings before interest, taxes, depreciation, and amortization) and free-cash-flow yield, not simple price/earnings — judge them on the building cycle, not any one child.[4]
• For the pure-plays: O-I Glass (OI) for glass containers (mind secular substitution, and that 2025's segment rebound sat inside a bottom-line net loss) and United States Lime & Minerals (USLM) for lime (high-margin and debt-free, but closely held and single-region). Martin Marietta (MLM) is the diversified way to own the emerging U.S. lime leader once the Lhoist deal closes. The two small ones — Smith-Midland (SMID) in precast and Oil-Dri (ODC) in ground minerals — are genuine but tiny, and SMID has disclosed material internal-control weaknesses.[3][4][5][6][17]
• For the structural-growth tails: own the premium, safer end, indirectly — advanced ceramics via Kyocera (KYO); specialty glass via Corning (GLW), and float makers positioned for the March–April 2026 duties (with the caveat that not every line can make qualifying solar glass); semiconductor-polishing abrasives via Fujimi and Entegris; code-driven mineral wool via Owens Corning (OC) and Rockwool (ROCK-B), or one layer downstream and furnace-free via TopBuild (BLD) and Installed Building Products (IBP); specialty minerals via Minerals Technologies (MTX), minding the talc overhang.[2][3][6]
• For everything else — where the value actually lives — go private. Most of this subsector is privately held (roughly 85% of ready-mix companies are family-owned or locally operated), so concentrated exposure to any child is a private proposition: local plant networks and regional real-asset moats (a mineral reserve + an efficient kiln/plant + a captive local market), PE roll-ups of fragmented ready-mix, precast, cut-stone, fabrication and abrasives producers, and the feedstock and distribution layers around them. Underwrite locally, not nationally — haul radius and competing plants inside it, utilization, contract-reset timing, approved-product status, and reserve life matter far more than any national growth forecast. The 9.5× and 10.3× EBITDA marks from the 2025 precast-and-pipe deals are the better public reference for a plant portfolio than the multiples paid for integrated national platforms.[4][5][6]

Near-term drivers to watch (forward-looking judgment, not federal fact):

1. Interest rates and the building cycle — the master swing factor for roughly two-thirds of the subsector, and the swing factor for whether 2026–27 recovers the volume lost since 2022.
2. The IIJA infrastructure pipeline and the data-center/reshoring buildout — the biggest demand tailwinds, feeding concrete, pipe, precast, insulation, construction chemicals, and CMP abrasives; remember that for the largest child, private commercial building still outweighs public work.
3. Natural-gas and energy costs — the near-term margin setter for every fired child.
4. Trade policy — the float-glass orders finalized in March–April 2026 and their two-sided effect on melters versus fabricators, plus tile, quartz, ceramics, abrasive-grain and cement measures.
5. The carbon and silica ratchets — the long-term cost overhangs (decarbonization capex at the cement and lime base; the engineered-stone silica reckoning in stone), with mineral wool sitting outside the second one.
6. Coal-plant retirement — the quiet structural squeeze on lime demand, gypsum feedstock, and cement's fly-ash supply at the same time.

The judgment. NAICS 327 is best understood not as an industry to "buy" but as a portfolio of five freight-moated, capital-heavy mineral-processing businesses filed under one code — dominated by a fragmented, private, half-the-subsector cement-and-concrete giant, flanked by mid-sized glass and other-nonmetallic wings, and completed by two small but concentrated specialists (clay/refractory and lime/gypsum) that hold the subsector's hottest deal-making and highest-growth tails. It looks near-atomistic nationally but is an oligopoly locally and in its concentrated sub-industries; the revised children make clear that the heat is where the concentration is while the forming is where the revenue is; it is overwhelmingly private and foreign-owned; and its 2022 headline dollars now sit above every current physical read except mineral wool. For most investors the honest conclusion is the same across all five children: this is a subsector where ownership, not trading, is how the money is made — and the durable edge is owning the premium, safer, freight-protected end, not buying the code broadly. For the full company detail, cost math, and citations, read the five child primers.

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Sources

Consolidated and renumbered from the five child primers (3271, 3272, 3273, 3274, 3279); subsector-level figures are our ingested Census ground truth for NAICS 327.

1. U.S. Census Bureau, 2022 Economic Census — Concentration by Largest Firms (receipts $164.79B; 9,104 firms; CR4 9.3%, CR8 16.9%, CR20 30.6%, CR50 45.3%; HHI 61) and County Business Patterns 2023 (15,317 establishments; 412,320 employees; $28.58B annual payroll; $6.88B first-quarter payroll), NAICS 327 and children. (Histometrics ingested federal ground-truth statistics, stats-327.md.) https://www.census.gov/programs-surveys/economic-census.html; https://www.census.gov/programs-surveys/cbp.html
2. Histometrics child primer — Clay Product and Refractory Manufacturing (NAICS 3271, and its children 32711/32712): receipts $9.334B; 866 firms; 1,036 establishments; 35,582 employees; CR4 22.4% / HHI 213; child splits ~28% / ~72% of shipments with HHIs of 954.7 and 256; FRED output index, tile consumption and import share, FGI Industries, Soul Patts/Glen-Gery, Wienerberger and Geberit margins, RHI Magnesita/Resco, China's >60% share of traded refractory raw materials, EPA NESHAP for brick and clay ceramics and refractory products, EPA WaterSense, Section 301 and ceramic-tile antidumping, and company filings (LIXIL, TOTO, Geberit, Kyocera, RHI Magnesita, Vesuvius, Wienerberger, Mohawk, Masco, Fortune Brands, Berkshire Hathaway).
3. Histometrics child primer — Glass and Glass Product Manufacturing (NAICS 3272 / 32721, and the four six-digit industries 327211/327212/327213/327215): receipts $31.89B; 1,349 firms; 1,541 establishments; 87,874 employees; CR4 32.1% with HHI suppressed; sub-industry shares and concentration; USITC per-pound and utilization data; float-glass AD/CVD sequence; cullet, energy and recycling data; and company filings (O-I Glass, Corning, Apogee, Gentex, D'Ieteren/Belron, Ardagh, Anchor Glass, Owens Corning).
4. Histometrics child primer — Cement and Concrete Product Manufacturing (NAICS 3273, and children 32731/32732/32733/32739): receipts $80.3B; 3,879 firms; 9,134 establishments; 189,833 employees; CR4 16.4% / HHI 100.5; child shares and concentration; freight radii; cement and ready-mix utilization; end-market mix; DOJ and state antitrust enforcement; Build America, Buy America mechanics; and company filings (CRH, Amrize, Cemex, Eagle Materials, Titan America, Commercial Metals, Vulcan, Martin Marietta, Knife River, NWPX, Smith-Midland, L.B. Foster, Quikrete/Summit).
5. Histometrics child primer — Lime and Gypsum Product Manufacturing (NAICS 3274, and children 32741/32742): receipts $11.95B; 124 firms; 265 establishments; 15,543 employees; CR4 64.7% / HHI 1,246.8; child CR4s of 82.6% and 84.1% with HHIs of 1,931 and 1,934.6; lime price-versus-volume split, captive production, end-use breakdown and NESHAP cost estimates; gypsum capacity, synthetic-feedstock transition, import reliance, customer and distribution concentration; EPA CCR beneficial-reuse exclusion; and company filings (USLM, Martin Marietta, Eagle Materials, Saint-Gobain, Knauf/USG, Home Depot/SRS, Lowe's).
6. Histometrics child primer — Other Nonmetallic Mineral Product Manufacturing (NAICS 3279, and children 32791/32799): receipts $31.33B; 2,979 firms; 3,341 establishments; 83,488 employees; CR4 19.3% / HHI 159.2; child splits ~12% / ~88% with CR4s of 50.5% (HHI suppressed) and 20.9% (HHI 172.3); sub-market HHIs for cut stone (52), ground minerals (503) and mineral wool (1,106); the IARC Group 3 mineral-wool classification; abrasive-grain import concentration and cost inflation; and company filings (Owens Corning, Rockwool, TopBuild, Installed Building Products, Minerals Technologies, Oil-Dri, Imerys, 3M, Saint-Gobain, Fujimi, Entegris, Caesarstone, Matthews, Atlas Energy Solutions, Smart Sand, Sika).
7. U.S. Geological Survey, Mineral Commodity Summaries 2026 — Cement, Lime, Gypsum, and industrial minerals (production, capacity, prices, import reliance and sources, captive production, abrasive-grain import shares). https://pubs.usgs.gov/periodicals/mcs2026/; https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cement.pdf; https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lime.pdf; https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-gypsum.pdf; https://pubs.usgs.gov/periodicals/mcs2026/mcs2026.pdf
8. American Cement Association, U.S. Cement Consumption Expected to Dip — Spring 2025 Economic Forecast (soft 2025 ≈ −1.6%, modest 2026, stronger 2027), 2025. https://www.cement.org/2025/05/19/u-s-cement-consumption-expected-to-dip-recession-not-a-foregone-conclusion-in-cement-industry-associations-spring-economic-forecast/
9. National Ready Mixed Concrete Association, 2023 Performance Benchmarking Survey and State of the Industry (per-yard economics and end-market mix; 15-year average pretax profit $3.31/yard and 4.3% pretax return on assets; 2005–2010 volume collapse), 2023. https://www.nrmca.org/wp-content/uploads/Performance_Benchmarking_Survey_and_State_of_the_Industry.pdf
10. U.S. International Trade Commission, Float Glass Products from China and Malaysia, Publication 5715 (Final), 2026, and Publication 5579 (Preliminary), 2025 — per-pound producer and processor values, capacity utilization, cost stack, margins, and substitutability. https://www.usitc.gov/publications/701_731/pub5715.pdf; https://www.usitc.gov/sites/default/files/publications/701_731/pub5579.pdf
11. U.S. Department of Commerce, International Trade Administration, "Final Affirmative Determinations in the AD/CVD Investigations of Float Glass Products from China and Malaysia" (2026); U.S. International Trade Commission, "USITC Makes Final Injury Determinations in Float Glass Products Investigations," Press Release 26-024 (March 2026); Federal Register, "Certain Float Glass from the People's Republic of China: Antidumping Duty Order" (April 2026). https://www.trade.gov/final-affirmative-determinations-antidumping-and-countervailing-duty-investigations-float-glass; https://www.usitc.gov/press_room/news_release/2026/er0323_68244.htm; https://www.govinfo.gov/app/details/FR-2026-04-06/2026-06647
12. U.S. International Trade Commission, "Sol-Gel Alumina Ceramic Abrasive Grain from China" (September 2025); Federal Register, "Certain Quartz Surface Products From India and the Republic of Türkiye: Continuation of Antidumping and Countervailing Duty Orders" (January 15, 2026); White & Case / USTR, "United States Finalizes Section 301 Tariff Increases on Imports from China" (2024). https://www.usitc.gov/press_room/news_release/2025/er0903_67493.htm; https://www.federalregister.gov/documents/2026/01/15/2026-00739/certain-quartz-surface-products-from-india-and-the-republic-of-trkiye-continuation-of-antidumping; https://www.whitecase.com/insight-alert/united-states-finalizes-section-301-tariff-increases-imports-china
13. U.S. Environmental Protection Agency, NESHAP/MACT standards for the Portland Cement, Brick and Structural Clay Products / Clay Ceramics, Refractory Products, Lime, and Glass manufacturing industries; Federal Highway Administration, Portland-Limestone Cement (FHWA-HRT-23-104). https://www.epa.gov/stationary-sources-air-pollution/neshap-portland-cement-manufacturing-industry-fact-sheet; https://www.federalregister.gov/documents/2015/10/26/2015-25724/neshap-for-brick-and-structural-clay-products-manufacturing-and-neshap-for-clay-ceramics; https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards; https://www.epa.gov/stationary-sources-air-pollution/lime-manufacturing-plants-national-emission-standards-hazardous; https://www.epa.gov/stationary-sources-air-pollution/glass-manufacturing-area-sources-national-emission-standards; https://highways.dot.gov/media/34231
14. U.S. Department of Energy, Industrial Decarbonization Roadmap (58% of 2015 U.S. cement-industry CO₂ from calcination), 2022. https://www.energy.gov/sites/default/files/2022-09/Industrial%20Decarbonization%20Roadmap.pdf
15. U.S. Occupational Safety and Health Administration, Respirable Crystalline Silica standard (29 CFR 1910.1053 / 1926.1153; PEL 50 µg/m³, action level 25 µg/m³); Mine Safety and Health Administration, "Lowering Miners' Exposure to Respirable Crystalline Silica" final rule (2024). https://www.osha.gov/silica-crystalline; https://www.msha.gov/silica-final-rule-30-cfr-part-60-resources
16. California engineered-stone silicosis record and regulatory response — Public Health Watch / Capital & Main (542 confirmed cases and 29 deaths as of April 2026; >90% silica content); KQED (Cal/OSHA action and the proposed >1% silica threshold; Australia's July 2024 ban); Stone World (STOP Act / SB 20 in full effect January 1, 2026). https://publichealthwatch.org/2026/04/14/california-silicosis-ban-lung-disease-stone-countertops/; https://www.kqed.org/news/12084910/california-steps-closer-to-ban-on-engineered-stone-after-silicosis-surge; https://www.stoneworld.com/articles/95545-californias-stop-act-sets-strictest-silica-rules-in-us-for-stone-fabricators
17. Martin Marietta Materials, Martin Marietta to Combine with Lhoist North America in $13.5 Billion Transaction (announced June 2026; $7B cash plus $6.5B stock) and Form 8-K / Transaction Presentation (Lhoist NA 2025 revenue ~$1.75B and adjusted EBITDA ~$786M; 2B+ tons of reserves; ~15× 2025 adjusted EBITDA with synergies; expected close in the second half of 2026), 2026. https://ir.martinmarietta.com/news-releases/news-release-details/martin-marietta-combine-lhoist-north-america-135-billion; https://www.sec.gov/Archives/edgar/data/916076/000095015726000758/ex99-2.htm
18. U.S. Energy Information Administration, 2025 Coal-Capacity Retirements (2.6 GW retired in 2025), 2025. https://www.eia.gov/todayinenergy/detail.php?id=67427
19. Federal Reserve Bank of St. Louis (FRED), Industrial Production: Clay Building Material and Refractories Manufacturing (IPG32712A) — 75.17 in 2025 versus 94.12 in 2022 (2017 = 100) — and Industrial Production: Glass Container Manufacturing (IPG327213A) — 109.0 in 2022 to 80.6 in 2025. https://fred.stlouisfed.org/series/IPG32712A; https://fred.stlouisfed.org/series/IPG327213A
20. American Society of Civil Engineers / Federal Highway Administration — Infrastructure Investment and Jobs Act (IIJA, ~$1.2T; ~$500B roads and bridges; ~$55B water, including $11.7B to the Drinking Water State Revolving Fund and $12.7B to the Clean Water State Revolving Fund). https://infrastructurereportcard.org/cat-item/iija-drinking-water-wastewater-stormwater/; https://www.environment.fhwa.dot.gov/legislation/authorizations/IIJA.aspx
21. U.S. Census Bureau, Construction Spending Release — December 2025 (private $1.6475T, −2.9%; residential $905.2B, −2.6%; nonresidential $742.4B, −3.1%; public $516.8B, +3.6%), 2025. https://www.census.gov/construction/c30/pdf/pr202512.pdf
22. ConstructConnect / Construction Owners, Data Centers Power U.S. Nonresidential Building Growth (~$42B in 2025, ~35% growth, ~42% of nonresidential building growth), 2025. https://www.constructionowners.com/news/data-centers-drive-nrb-growth
23. Tile Council of North America via TileLetter, 2025 U.S. Ceramic Tile Market Update (consumption 2.57 billion sq ft, down 4.9%; domestic shipments 707.7 million sq ft, lowest since 2012; imports 72.4% of consumption by volume), 2026. https://www.tileletter.com/2025-u-s-ceramic-tile-market-update/
24. Grand View Research / Mordor Intelligence, Advanced Ceramics Market (~$12.86B in 2025 rising to ~$17.24B by 2030, ~6% CAGR; global and broader than NAICS 3271, so directional only), 2025–2026. https://www.grandviewresearch.com/industry-analysis/advanced-ceramics-market