Brass Machining and Precision Parts in Billings, MT — C360, C260 & Naval Brass Suppliers

C360 (UNS C36000, free-cutting brass) is the most machinable metallic alloy in common use — its machinability rating of 100 on the standardized scale makes it the benchmark against which all other metals are measured. The lead content (2.5–3.7%) creates chip-breaking inclusions that produce tight, curl chips at high spindle speeds, allowing Billings CNC turning centers to run brass at 600–900 SFM with carbide tooling without coolant in many cases. This translates directly to cycle times that are a fraction of what the same geometry would require in stainless steel, making C360 the default specification for high-volume precision fittings, valve stems, coupling bodies, and instrumentation adapters. Billings's industrial maintenance and oil-field supply sector consumes C360 brass fittings in quantity — NPT-threaded fittings, compression fitting bodies, needle valve stems, gauge manifolds, and pneumatic actuator components all commonly arrive from Billings machine shops in C360. The grade's corrosion resistance is adequate for non-ammonia water, petroleum products, and most non-oxidizing acids, which covers the majority of refinery utility and instrument service applications. Buyers should note the RoHS and California Proposition 65 lead content restrictions — for potable water applications or food-contact service, specify C360 only if the fitting manufacturer's NSF 61 listing covers the specific product, or switch to a lead-free brass such as C69300 (Eco Brass) which meets lead-free plumbing requirements.

C260 (70% copper, 30% zinc, UNS C26000) is the brass grade chosen when forming, drawing, or cold-working operations dominate the manufacturing process. Its ductility — elongation of 45–55% — allows deep drawing, stamping, and tube bending operations that would crack higher-zinc or leaded grades. The name 'cartridge brass' comes from its original application in ammunition cases, and that heritage reflects exactly the forming capability that makes it valuable: a cartridge case undergoes severe cold-work in a single draw-and-form operation without tearing. In Billings's industrial context, C260 appears as tube for heat exchanger and radiator applications in heavy equipment, drawn shells for precision instrument housings, and bent tube assemblies for hydraulic and pneumatic line sets in agricultural machinery. The material work-hardens significantly during cold-forming — a severe draw can raise hardness from H01 to H08 temper — so intermediate anneals are sometimes required for multi-stage forming sequences. Billings fabricators with tube bending and hydroforming capability process C260 tube for equipment OEMs; the tube's clean formability and good corrosion resistance in petroleum and water service make it a regular production material. Machining C260 is less efficient than C360 due to the absent lead addition, but it is still more machinable than most steels and stainless grades.

Naval brass (C464, UNS C46400) adds approximately 0.75–1.0% tin to a 60/40 copper-zinc base, and that single addition dramatically improves resistance to dezincification — the selective leaching of zinc from the brass matrix that causes traditional high-zinc brasses to fail in hot or aggressive water service. In dezincification, the zinc dissolves into solution over time, leaving a porous, weak copper sponge that lacks mechanical integrity and eventually fails. Naval brass's tin inhibits this process, making it the appropriate specification for valve bodies, pump housings, and marine-service fittings where hot water or corrosive brine contact is expected. In Billings's industrial context, naval brass appears in the produced-water handling infrastructure associated with oil field operations, water treatment equipment serving municipal and industrial clients, and refinery cooling water system components. Hot water heater fittings, industrial valve bodies for steam condensate service, and heat exchanger headers in water-cooled systems are specific applications. Naval brass's machinability rating of approximately 30 (versus 100 for C360) means machining costs are higher, which is why C360 is preferred wherever the dezincification risk is low. For applications with continuous hot-water or brine exposure above 140°F, the naval brass specification is not optional — it is the engineering-correct choice, and value engineering it away often results in premature failures that cost far more than the original material premium.