Producer
Waupaca Foundry
World's largest independent gray and ductile iron foundry; headquartered in Waupaca, Wisconsin. Owned by Proterial Ltd. (formerly Hitachi Metals — renamed 2023 after Bain Capital-led consortium acquired it from Hitachi in 2021). Five foundry/machining plants: Plants 1, 2/3, and machining in Waupaca WI; Plant 4 in Marinette WI; Plant 5 in Tell City IN. ~4,000 employees; ~1.4-2 million metric tons/year capacity across all plants; castings from 2 lbs to 350 lbs in gray, ductile, high-strength ductile, austempered ductile, and compacted graphite iron. Confirmed John Deere "Partner-Level Supplier" (highest supplier tier) — 40+ year relationship. Products for ag OEMs: housings, tractor weights, hubs, flywheels, axle carriers, sheaves. Also serves automotive (Toyota confirmed), commercial vehicle, and industrial markets.
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Goods downstream
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Facilities
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Stories
What they make
3 inputs Waupaca Foundry supplies
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Where they make it
3 facilities
Waupaca Foundry – Plant 4 (Marinette, Wisconsin) →
USWisconsin
Waupaca Foundry Plant 4 in Marinette, Marinette County, Wisconsin. 12 tons/hour melt capacity. Gray and ductile iron castings for off-highway (agricultural, construction) and automotive markets. Named as one of the three Waupaca plants supplying John Deere alongside Plants 2/3 (Waupaca WI) and Plant 5 (Tell City IN).
Waupaca Foundry – Plant 5 (Tell City, Indiana) →
USIndiana
Waupaca Foundry Plant 5 in Tell City, Perry County, Indiana. Produces gray, ductile, and compacted graphite iron castings. Serves agricultural, commercial vehicle, and automotive markets. CGI (compacted graphite iron) capability is notable — higher mechanical requirements than standard gray iron; used in engine blocks demanding strength between gray and ductile iron. Part of Waupaca's five-plant national network under Proterial (formerly Hitachi Metals) ownership.
Waupaca Foundry — Waupaca, WI →
USWaupaca, Wisconsin · iron_foundry
Waupaca Foundry headquartered here; Plants 1, 2/3, and machining center in Waupaca, Waupaca County, Wisconsin. Plants 2/3 are the largest complex (900+ employees, 665,850 sq ft on 90 acres). Plant 1 has 600+ employees, 322,988 sq ft. Combined Waupaca WI operations are the largest single-location iron foundry complex in North America. Confirmed John Deere "Partner-Level Supplier" (40+ year relationship). Owned by Proterial Ltd. (formerly Hitachi Metals, renamed 2023; owned by Bain Capital-led consortium that acquired it from Hitachi in 2021 for ~$3B). A Japanese-heritage PE-owned company controls America's largest iron foundry.
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Agricultural Castings (John Deere Primary)
45%Automotive Castings
30%Commercial Vehicle & Industrial
20%Ownership: Proterial Ltd. (Japan)
5%
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Did you know2024
[single-source] Waupaca Foundry — America's largest iron foundry, the primary external casting supplier for John Deere's agricultural equipment, a 40-year strategic partner — is owned by Proterial Ltd., a Japanese company. Proterial was formerly Hitachi Metals; Hitachi sold it in 2021 to a consortium led by Bain Capital, with minority stakes held by Nippon Steel and JFE Steel. The US agricultural equipment supply chain's most critical independent casting facility is therefore Japanese PE-backed, with major Japanese steel companies as minority owners. This ownership structure has received no public policy scrutiny despite the facility's strategic importance to US food production infrastructure.
Waupaca Foundry ↗Capacity2023
Waupaca Foundry and Metglas are both owned by Proterial Ltd. (formerly Hitachi Metals, Japan) — meaning the same Japanese private-equity-backed conglomerate controls two of North America's most strategically significant industrial materials facilities: the world's largest independent iron foundry (Waupaca — farm equipment, automotive, commercial vehicle castings) and the sole US domestic amorphous metal ribbon producer (Metglas Conway SC — for energy-efficient transformer cores). Foreign ownership of US critical industrial capacity receives less policy scrutiny than semiconductor or defense supply chain concentration. Yet Proterial's simultaneous ownership of the foundry that makes John Deere's tractor components and the plant making transformer core materials for US grid modernization represents concentrated Japanese control over two distinct but strategically significant US manufacturing sectors.
Proterial Ltd. ↗Chokepoint2024
Waupaca Foundry operates 7 iron foundries (WI, IN, PA, TN) and melts more than 10,000 tons of iron daily — the world's single largest independent gray and ductile iron casting operation. With 4,400+ employees, it has supplied agricultural equipment OEMs for 65+ years. Its scale and customer relationships make it a critical node in the external casting supply chain for CNH Industrial and AGCO, which lack John Deere's captive foundry advantage.
Waupaca Foundry ↗Origin2023
Waupaca Foundry was founded in 1955 in Waupaca, Wisconsin as a small gray iron foundry serving local agricultural equipment manufacturers. Over decades it grew to become the world's largest independent gray and ductile iron foundry through organic capacity expansion and operational excellence in high-volume iron casting. The foundry is known for continuous improvement culture and lean manufacturing — achieving Six Sigma levels of consistency for commodity castings. Hitachi Metals (Japan) acquired Waupaca in 2016 to gain access to North American automotive and agricultural casting markets. After Bain Capital-led consortium bought Hitachi Metals from Hitachi in 2021 (renaming it Proterial Ltd.), Waupaca became part of Proterial's North American industrial holdings — the same Japanese-controlled company that also owns Metglas (amorphous metal ribbon for transformer cores).
Waupaca Foundry ↗