Brass Suppliers Kokomo IN

Karl Gillihan

🟡 BRASS

Brass Machining and Fabrication Suppliers in Kokomo, IN — Hydraulic Fittings, Valve Hardware, and Precision Turned Parts

Brass has been a constant in Kokomo's manufacturing supply chain long before electrification entered the picture — hydraulic fittings, valve seat inserts, solenoid connectors, and fluid metering orifices throughout Stellantis's transmission assemblies run on free-machining C360 brass turned to tight tolerances by the area's precision turning shops. C260 cartridge brass provides the formability for drawn and stamped components. Naval brass extends performance into more demanding corrosion environments. Kokomo's tradition of precision machining for automotive fluid systems makes it one of Indiana's strongest corridors for brass turned and formed components, and ManufacturingBase maps that supply base for buyers who need qualified sources fast.

ISO 9001IATF 16949

C360 free-cutting brass — 61.5 percent copper, 35.5 percent zinc, 3 percent lead — is arguably the most machinable metallic material in common engineering use. Its machinability rating of 100 on the standard brass machining index means it is the benchmark against which all other metals are measured. Swiss-type CNC turning centers and multi-spindle screw machines running C360 bar stock produce transmission fluid fittings, valve seat inserts, solenoid terminal studs, and orifice plates at cycle times that no steel or aluminum alternative can match. In Kokomo's transmission-focused precision turning shops, C360 parts run at spindle speeds of 3,000 to 6,000 RPM with feed rates that produce clean chip break and Ra 32 to Ra 63 microinch surface finishes in a single pass without secondary finishing. Tolerance capability on C360 in Swiss turning is excellent — diameter tolerances of plus or minus 0.0005 inch, bore concentricity within 0.001 inch, and thread class 3A or 3B quality on machined threads are routine. This precision matters for transmission hydraulic fittings where leak-free assembly under 300 PSI ATF pressure depends on accurate thread engagement and sealing face geometry. Valve seat inserts machined from C360 require ID tolerances of plus or minus 0.001 inch for press-fit into aluminum valve body bores, with press-fit interference of 0.001 to 0.003 inch over the bore diameter providing retention force against hydraulic pressure. Lead content in C360, while essential for its machinability, is a regulatory consideration for components that may contact potable water or be subject to RoHS restrictions in European markets. For fluid handling components in automotive ATF circuits — not potable water — lead content is generally not a compliance issue. However, buyers sourcing for export markets or consumer product applications should verify applicable regulations before specifying C360 and consider lead-free alternatives such as C37710 bismuth-selenium brass if required.

C260 Cartridge Brass for Formed and Stamped Components

C260 — 70 percent copper, 30 percent zinc — is the standard choice when brass must be deep-drawn, formed, or stamped into complex shapes. Its combination of moderate strength (tensile 76,000 psi in the half-hard condition), high ductility (elongation 43 percent in the annealed condition), and excellent formability without season cracking risk makes it the default for drawn shells, formed brackets, heat exchanger fins, and stamped electrical housings. In the Kokomo automotive supply chain, C260 appears in brass sleeve bearings, bushing shells, and formed connector housings within transmission electrical assemblies. Deep drawing of C260 to draw ratios of 2.0 to 2.5 is achievable in a single draw operation, producing cup depths of twice the cup diameter without intermediate anneals. This is substantially better than steel sheet draw ratios of 1.6 to 2.0 and enables complex housing geometries from a single blank, reducing assembly complexity. Bending C260 sheet to inside bend radii of 0.5 times material thickness in the annealed condition is achievable without cracking, tightening to 0.25 times material thickness in the quarter-hard condition — flexibility that suits complex formed bracket profiles. Surface quality of C260 stampings is important when the parts are destined for plating or decorative finish. Blanked edges from progressive dies must be free of burrs over 0.003 inch height to plate uniformly without high-spot buildup. Formed surfaces must be free of deep tool marks that telegraph through thin plating deposits. Kokomo-area stamping shops running C260 for automotive applications perform in-process inspection of edge condition and surface quality using profilometry and visual standards established at PPAP to maintain consistent incoming quality at their plating suppliers.

Secondary Operations and Quality Assurance for Brass Components

Brass machined and stamped components in Kokomo's automotive supply chain require secondary operations ranging from passivation to plating, and quality documentation that meets automotive PPAP and APQP standards. Bright dipping — acid immersion that removes machining oils and surface oxides to produce a shiny bare brass surface — is a common pre-plating operation performed in-house by larger finishing shops or subcontracted to regional metal finishing facilities. Tin plating and nickel plating are the most common finish requirements for brass electrical contacts and hydraulic hardware; decorative chrome is essentially absent from automotive manufacturing due to environmental regulations. Dimensional inspection of brass precision turned parts uses calibrated bore gauges, air gauges, and CMM equipment. For transmission hydraulic fittings where thread form, pitch diameter, and sealing face geometry all affect leak-free assembly, 100 percent gauging at critical features is standard practice in Tier 1-adjacent production environments. Thread gauging with go/no-go gauges per ASME B1.2 for inch threads and ISO 1502 for metric is verified at setup, at specified first-piece inspection intervals, and at end-of-run. Sealing face runout and squareness are measured with dial indicator fixtures, with acceptance criteria documented in the approved control plan. Kokomo shops running brass for automotive programs understand that a dimensional nonconformance that escapes inspection costs far more in warranty and recall risk than a scrap rate at the source. Quality cultures built around zero-escape targets and statistical process control on key features are the differentiator between shops that retain long-term automotive programs and those that lose them after the first escape event. ManufacturingBase supplier profiles include quality incident history and customer retention data where available, helping buyers identify sources with proven track records before committing production volumes.

Naval Brass and Specialty Grades for Enhanced Performance

Naval brass — C464, approximately 60 percent copper, 39.2 percent zinc, 0.75 percent tin — gains its name from its original application in marine hardware, where the tin addition dramatically improves dezincification resistance compared to binary copper-zinc brasses. Dezincification is the selective leaching of zinc from brass in certain water chemistries — soft water, slightly acidic conditions, high chloride — leaving a porous copper-rich layer that loses structural integrity without visible surface change. In automotive coolant systems and hydraulic circuits using water-based fluids, dezincification risk is real, making naval brass or inhibited brass the specification requirement for fittings and manifolds in those fluid circuits. C464 naval brass bar is machined at roughly 40 to 50 percent of C360's machinability rating — cycle times are longer and tooling consumption higher than free-cutting brass, but still competitive with steel for the same part. Tensile strength in the half-hard condition runs 85,000 to 95,000 psi, meaningfully stronger than C360 at 68,000 psi, which matters for pressure fittings and structural fasteners. Kokomo-area machine shops with coolant system fitting programs maintain C464 in their raw material inventory alongside C360, selecting the grade at design time based on fluid compatibility requirements specified by the OEM. For applications combining high strength with corrosion resistance — marine deck hardware, architectural fasteners, and high-stress fluid fittings — Manganese bronze (C675) and aluminum bronze (C630) extend brass-family performance into ranges that approach medium-carbon steel while maintaining far superior corrosion resistance. These high-strength copper alloys occupy a niche position in Kokomo's supply chain, mostly encountered in heavy-duty hydraulic fittings, pump housings, and worm gear components in industrial equipment manufactured in the region's non-automotive industrial base.

Frequently Asked Questions

C360 free-cutting brass is the standard grade for precision CNC turned hydraulic fittings in automatic transmission applications. Its machinability rating of 100 — the benchmark — allows turning centers and Swiss machines to produce complex fitting geometries with tight tolerances at cycle times that keep piece-part costs competitive with alternatives. Straight thread O-ring boss fittings, pipe thread fittings in NPT and BSPP, and push-to-connect body components all machine cleanly in C360 with thread class 3A or 3B quality and sealing face Ra 32 to Ra 63 surface finish achievable in finishing passes. For transmission applications with water-glycol coolant circuits rather than pure ATF, specify C464 naval brass instead of C360 to gain dezincification resistance. The machinability penalty — 40 to 50 percent of C360 versus the 100 percent baseline — adds cycle time and cost but is necessary when water-based fluid contact exists. If your fittings are in a pure ATF circuit with no water contact, C360 is appropriate. Confirm the fluid composition and operating temperature range with your system engineer before specifying grade, as ATF formulations vary by OEM and generation, and some synthetic ATF formulations contain detergents or additives that can affect brass alloy stability over long service periods.

C260 cartridge brass is the preferred brass grade for deep drawing precisely because of its high ductility and uniform deformation behavior. In the fully annealed condition, C260 has elongation exceeding 40 percent and n-value (strain hardening exponent) of approximately 0.55, supporting draw ratios up to 2.5 in a single operation. For a 2-inch diameter cup, this means drawing to 5-inch depth in one hit without intermediate annealing, which is not achievable with most steel grades. The forming limit for C260 before intermediate anneal is substantially higher than C360, which work-hardens more rapidly and requires annealing at lower draw depths. Die geometry for C260 deep drawing uses a land radius of 4 to 8 times material thickness on the die face to allow smooth material flow without scoring, and a punch nose radius of 6 to 10 times material thickness to prevent localized thinning at the punch bottom. Blank holder force must be controlled to prevent wrinkling in the flange while not restricting metal flow so severely that it causes tearing in the punch radius zone. Lubrication with a zinc stearate or light oil is standard for C260 drawing. Kokomo-area stamping shops that have drawn steel automotive components can adapt to C260 deep drawing with die adjustment and process qualification, though C260's different springback and ductility profile means first-article trials are essential before committing production tooling.

Brass has a limited but specific role in EV battery component applications. The fundamental issue is electrical conductivity: C360 brass at 26 percent IACS is a poor conductor compared to copper at 100 percent IACS or even aluminum at 61 percent IACS. For current-carrying busbars and cell interconnects where resistive heating in a high-current battery circuit is a thermal management challenge, brass is the wrong material choice. Those applications specify C101 or C110 copper as described elsewhere in ManufacturingBase's copper coverage for Kokomo. Brass does appear in EV applications as structural hardware and non-current-carrying electrical components: terminal block inserts, battery management system connector housings, threaded inserts for plastic enclosures, and non-structural fasteners where corrosion resistance and thread quality matter more than electrical conductivity. In these roles, brass's corrosion resistance, excellent machinability for complex geometries, and self-lubricating thread engagement make it superior to steel. Brass standoffs, insert nuts, and mounting hardware within battery management system electronics are the most common brass applications in EV battery assembly. For any component that carries significant current in a Samsung SDI module assembly, verify the conductivity requirement against design specifications before substituting brass for copper.

Brass raw material lead times in Kokomo are among the shortest of any engineering alloy because C360 bar stock in standard diameters — 0.125 inch through 4 inch — is stocked inventory at Indianapolis-area service centers with next-day to two-day delivery to Howard County. C260 strip in standard gauges is similarly stocked. Naval brass C464 and other specialty brass grades may run three to five days from Indianapolis distributors. This short raw material lead time means brass machined part delivery schedules are driven primarily by shop queue and machining time rather than material availability. For precision turned C360 parts — fittings, valve seats, connector hardware — first-article lead times run two to four weeks from purchase order to delivery in typical shop conditions. Simple turned parts with two to three operations and gauged inspection run two to three weeks; complex multistep Swiss-turned parts with multiple diameters, features, and threads run three to five weeks for first articles. Production releases on approved parts, particularly with blanket orders and scheduled releases, compress to one to two weeks for most brass turned part programs. Stampings from C260 in active tooling run one to three weeks per production release. If plating is required — tin, nickel, or chrome — add one to two weeks through regional finishing shops. Total lead time from PO to plated, inspected brass parts typically runs four to six weeks for first articles and two to four weeks for production releases.

RoHS (Restriction of Hazardous Substances) Directive and comparable regulations restrict lead content in electrical and electronic equipment sold in the EU to 0.1 percent by weight in homogeneous materials, with some documented exemptions. C360 at approximately 3 percent lead exceeds this threshold, making it non-compliant for most RoHS-scoped applications. If your brass components are destined for electronic assemblies, consumer products, or vehicles sold in EU markets without an active RoHS exemption covering brass machinable components, you must specify a lead-free or low-lead alternative. The two most common lead-free alternatives are C37700 bismuth brass (bismuth and selenium replace lead as chip breakers) and C69300 eco brass (silicon replaces lead). C37700 bismuth brass has a machinability rating of approximately 70 to 80 percent of C360 — slower cycle times and higher tooling consumption but much better than C360's lead-free plain brass alternatives. C69300 eco brass machines at roughly 60 percent of C360 and also offers improved dezincification resistance. Both lead-free grades are available from Wieland and Mueller brass suppliers serving Midwest markets, typically with one to two week lead time premium over commodity C360 bar stock. Confirm with your legal and compliance team whether a specific RoHS exemption applies to your application before switching grades, as automotive applications have historically maintained exemptions that consumer electronics do not. ManufacturingBase can connect you with Kokomo-area shops that have already qualified lead-free brass processes for EU-export programs.

Last updated: July 2026

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