Copper Fittings (refrigerant-grade)

Major U.S. copper tube manufacturer (HQ Sauget, IL); owned by Marmon Holdings, itself a Berkshire Hathaway company. Cerro Flow is the second-largest domestic copper tube producer with an estimated 15-20% of the U.S. market. Sauget, IL plant produces ASTM B88 plumbing tube and industrial copper tube. As a Marmon/Berkshire company, Cerro Flow operates with significant financial stability and long-term capital commitment. Cerro Flow competes directly with Mueller Industries in the plumbing and HVAC copper tube market but lacks Mueller's vertical integration into copper mining.

Hailiang Group Co., Ltd. (SHEX: 002171, HQ Zhuji, Zhejiang Province; the world's largest copper products manufacturer by volume) produces both copper tube and brass rod at its Zhuji complex. Hailiang is a major global brass rod supplier — its brass rod production includes C36000-equivalent free-machining alloys as well as architectural and industrial brasses. US antidumping duties (AD/CVD Order A-570-964 and related orders) have been levied on Chinese brass rod including Hailiang's exports, but Chinese brass rod continues to flow into global supply chains through third-country transshipment and via Hailiang's overseas expansion. Hailiang has been named in US Commerce Department antidumping proceedings and has operated manufacturing in Southeast Asia partly to serve export markets outside the tariff scope. China's share of global brass rod production is approximately 60-65% by volume, with Hailiang and Ningbo Jintian as the two largest producers.

Major European copper tube and copper rod manufacturer (HQ Osnabrück, Germany); owned by Intek Group. KME (formerly part of IMI plc and then renamed from Europa Metalli/KM Europa Metal) is one of Europe's leading copper and copper alloy fabricators. Produces plumbing copper tube (European DIN/EN standard equivalent), industrial copper tube, and copper rod for European construction and HVAC markets. Manufacturing facilities in Germany, Italy, France, and Spain. KME's Osnabrück facility is one of the largest copper fabrication plants in Europe.

Mueller Industries, Inc. (NYSE: MLI, HQ Memphis TN; ~$3.5B revenue) is North America's dominant vertically integrated brass rod and plumbing fittings manufacturer. Mueller Brass division operates the Port Huron, Michigan brass rod plant — one of the largest brass rod extrusion facilities in North America, producing C36000 free-machining brass rod and lead-free alloys (C69300 eco-brass) for plumbing fittings manufacturers. Mueller also manufactures finished brass fittings under the Streamline® brand and valves under the Mueller B&K and Klauke brands. Mueller's vertical integration — from brass rod through finished fittings — is unique among North American competitors. The company supplies the majority of brass plumbing fittings used in US residential construction. Mueller's Port Huron plant is one of only two significant US-domestic free-machining brass rod extrusion facilities.

German family-owned copper products conglomerate (HQ Ulm, Germany), founded 1820 in Vöhringen. Dominant global supplier of copper alloy strip for electronic connector terminals — the world's largest flat-rolled copper products company by volume. In 2024 Wieland made two major moves: (1) announced a $500 million modernization/expansion of its East Alton, Illinois plant (formerly the Olin Brass flagship site, first opened 1916) to add a new hot-rolling mill and casting unit targeting EV and connector-strip growth, with Illinois contributing ~$231M in incentives; (2) acquired Aurubis's Buffalo, NY flat-rolled copper strip facility (Aug 30, 2024), absorbing ~500 employees and its specialty connector-grade strip capacity. Wieland's connector alloys portfolio includes new grades K58 and K75 (high-strength, miniaturization-ready) and the established STOL series. Also supplies ACR copper tube (Pine Hall NC), plumbing tube, and industrial copper products. In CuNiSi/Corson alloys Wieland competes directly with Japanese producers for automotive connector strip.