🟡 BRASS
Brass Machining and Precision Turned Parts in Janesville, WI — C360, C260, Naval Brass
Brass earns its place in Janesville's manufacturing output through a combination of properties that no single alternative material matches: free-machining C360's machinability index of 100 makes it the benchmark against which all other metals are measured, C260 cartridge brass's deep drawability supports formed components with geometry impossible to machine, and Naval brass resists dezincification in marine and salt-spray environments where standard C360 would fail in service. Buyers in Rock County's automotive, industrial equipment, and fluid systems sectors run brass programs across screw machining, CNC turning, and progressive stamping — all available from established Janesville-area suppliers.
ISO 9001IATF 16949ISO 14001
Brass Grades and the Applications They Serve in Janesville's Industrial Sectors
C360 free-machining brass — 61.5 percent copper, 35.5 percent zinc, 3 percent lead — is the dominant precision machining grade in Janesville and everywhere else high-volume turned-part production runs. Its machinability index of 100 sets the standard: chips break cleanly, tools stay sharp longer than on any other structural metal, and surface finishes of 32 Ra or better are achievable on standard CNC lathes without special tooling or technique. The lead content that enables free machining also introduces environmental and regulatory considerations; many automotive programs now require lead-free alternatives, and C353 bismuth brass (a lead-free grade with similar machinability) or silicon brass are increasingly substituted where lead-free compliance is mandated.
C260 cartridge brass — 70 percent copper, 30 percent zinc — is the forming and drawing grade. Its elongation of 40 to 65 percent in the annealed condition allows deep drawing ratios (cup diameter to blank diameter) of 2.0 or better in a single draw, which is why it has historically been used for cartridge cases — the application that gave the grade its name. In Janesville's industrial market, C260 runs through progressive stamping dies for electrical terminals, fluid-path covers, decorative hardware, and formed connector shells where complex geometry is more efficiently produced by forming than by machining.
Naval brass — C464, 60 percent copper, 39.2 percent zinc, 0.75 percent tin — is specified where dezincification resistance matters. Standard C360 and C260, in acidic or chloride-rich environments, can undergo selective leaching of zinc from the alloy matrix (dezincification), leaving a weak, porous copper sponge that fails mechanically long before the expected service life. The tin addition in Naval brass inhibits this mechanism, making it the right grade for valve bodies, marine hardware, and fluid system components exposed to treated water, seawater, or aggressive industrial process fluids in Janesville's heavy-equipment and industrial supply chain.
CNC Turning and Screw Machine Production of Brass Parts
Brass screw machine work has historically been the highest-volume precision machining category in American manufacturing, and while modern CNC Swiss-turn and gang-tool lathes have largely replaced the cam-driven screw machines of the past, the production logic is identical: run high-spindle-speed turning of brass bar stock with minimal tool engagement time per piece, producing thousands of turned parts per shift with consistent dimensional control. Janesville shops with Swiss-turn capability can hold diameters to +/-0.0003 inch on C360 brass parts from 0.050 to 1.25 inch diameter, with cross-features, threads, and undercuts produced in a single clamping.
For larger brass components — valve bodies above 2 inch diameter, manifold blocks, and machined fittings — CNC turning centers and 4- or 5-axis machining centers take over from Swiss equipment. C360's machinability means cycle times on these larger components are short relative to stainless or alloy steel, which keeps pricing competitive even at moderate volumes. Internal thread quality in C360 is excellent: the free-machining character allows clean thread form without the torn threads that plague ductile materials at small thread diameters.
Dimensional stability between operations is a brass advantage: its thermal expansion coefficient of approximately 11.2 millionths per degree Fahrenheit is close to aluminum and lower than some engineering plastics, but crucially, brass does not require stress relief between operations as some aluminum alloys do. Machined brass parts can be inspected immediately after cutting without waiting for thermal stabilization, which speeds throughput on time-sensitive programs.
Forming, Stamping, and Finishing for Brass Components
Progressive and transfer die stamping of C260 cartridge brass produces the electrical terminals, connector housings, shield clips, and formed fluid-path covers that Janesville's automotive and industrial supply chains consume in high volume. C260 in the half-hard H02 temper balances formability with spring-back predictability for terminal and contact applications; full-hard H04 condition is used for spring contact elements where elastic recovery after deflection must be maintained through service life. Die designers in Rock County's tooling operations understand the springback curves for C260 and compensate their bend angles accordingly.
Finishing brass components for automotive and industrial service in Janesville typically involves tin plating for corrosion protection and solderability, bright nickel for decorative and wear-resistant surfaces, and chromate conversion coating for moderate corrosion resistance without plating buildup on close-tolerance features. Electroless nickel is available for uniform coverage on complex geometries where electroplated nickel builds unevenly. Raw machined C360 brass is acceptable for indoor service where oxidation is cosmetically tolerable, but most production programs specify a surface treatment for consistency and customer presentation.
Deburring of brass machined parts uses vibratory tumbling with ceramic or plastic media for high-volume lots, removing edge burrs and imparting a uniform surface appearance without dimensional change on non-critical features. Precision edge breaks on sealing surfaces and thread lead-ins are done by hand or by CNC chamfering cycle to maintain the controlled break geometry required by the part drawing.
Lead-Free Brass Compliance and Automotive Program Requirements
The automotive industry's push toward lead-free materials — driven by regulatory pressure under RoHS, ELV (End-of-Life Vehicle Directive in Europe), and NSF 61 for potable water contact in North America — has created a genuine grade-selection challenge for brass programs in Janesville's supply chain. C360's machinability is enabled by its 3 percent lead content, and lead-free alternatives sacrifice some machinability: bismuth-brass grades like C89520 offer machinability indexes of 70 to 80 versus C360's 100, silicon brass (C87600) runs at similar levels. The cycle time penalty is real but manageable for programs that genuinely require lead-free compliance.
Janesville shops serving automotive Tier 1 suppliers are accustomed to material compliance documentation — RoHS certificates of conformance, material data sheets with full substance declarations, and IMDS (International Material Data System) entries for OEM material tracking systems. Buyers should specify lead-free requirements explicitly at the RFQ stage and confirm that the shop's material certification process generates the substance declaration documentation their compliance team requires. The material cost difference between C360 and lead-free grades is modest; the documentation discipline is the more important differentiator between shops that can and cannot support automotive lead-free programs.
Sourcing Strategy and Volume Economics for Brass in Southern Wisconsin
Brass bar stock is one of the most universally available metals in the regional service center network. C360 round bar in diameters from 0.25 inch to 4 inch and hexagonal stock in common across-flats sizes is stocked by Milwaukee and Rockford service centers with same-day or next-day delivery to Janesville shops. C260 sheet and strip in standard gages and tempers is similarly available, with larger coil sizes for stamping programs available on 3 to 5 day lead times. Naval brass and specialty alloys require 1 to 2 week procurement from specialty distributors.
Unit pricing for brass machining scales favorably with volume: setup and programming amortization on simple turned parts (4 to 8 features) becomes negligible above 500 pieces, and production pricing at 2,500 to 25,000 pieces per year is the most competitive tier for most Janesville shops. Swiss-turn programs running 50,000 to 500,000 pieces per year achieve the lowest unit costs, with bar feed running near-continuously and operator oversight on multiple machines simultaneously. Buyers with high-volume brass turning programs should benchmark Janesville Swiss-turn shops against Asian offshore alternatives and account for full landed cost, quality system depth, and supply chain risk in the comparison — regional sourcing often wins on total cost and program stability for volumes below 1 million pieces per year.
Frequently Asked Questions
C360 free-machining brass contains 3 percent lead, which disperses through the alloy matrix as discrete particles that act as chip breakers during cutting. When a tool shears through C360, the chip fractures at these lead inclusions into short, clean segments rather than forming the long, stringy, tangled chips that pure copper or C260 produce. The practical result is a machinability index of 100 — the reference value against which all other metals are compared — meaning C360 machines faster, with less tool wear, at better surface finish, and with fewer tool-change interruptions than any other structural metal. A shop that produces 200 pieces per hour of a given turned profile in 4140 steel might produce 600 to 800 pieces per hour in C360 brass, not because speeds are dramatically higher but because tool changes are rare, chip management is effortless, and threading and boring operations are clean the first time. For high-volume precision turned components in Janesville's automotive and industrial supply chains, C360 is the default unless lead-free compliance is mandated.
Naval brass (C464) is the right choice when dezincification resistance is a service requirement. Dezincification — the selective leaching of zinc from the brass matrix, leaving a weak copper sponge — occurs in acidic water, seawater, and some industrial process fluids, particularly in stagnant conditions at temperatures above 60 degrees Celsius. Standard alpha-beta brass alloys like C360 (61.5 percent copper) and C260 (70 percent copper) are susceptible at different rates — lower-copper brasses dezincify faster. The 0.75 percent tin in Naval brass inhibits this electrochemical mechanism, extending service life in marine and aggressive water chemistry applications by a factor of 5 or more compared to C360 in the same environment. Janesville shops serving fluid-system and industrial valve customers specify Naval brass for valve bodies, fitting bodies, and manifold components destined for water treatment, marine, or process fluid service. Buyers should call out the service environment in their drawings or specifications rather than leaving grade selection to the shop, as the performance difference in field service is significant.
Swiss-style CNC lathes running C360 brass in Janesville hold outside diameters to +/-0.0003 inch as a production standard on parts up to approximately 1.25 inch diameter, with tighter tolerances of +/-0.0001 inch achievable on critical features with appropriate in-process gauging and temperature-controlled inspection. Concentricity between turned diameters is typically 0.0003 to 0.0005 inch total indicator reading (TIR) on Swiss equipment where the part is supported at the guide bushing during cutting. Thread quality on standard 2A/2B inch and metric threads in C360 is excellent — clean flanks and consistent pitch diameter from the material's free-machining character. Surface finish of 32 Ra microinch or better is standard on turned OD features in C360; 16 Ra is achievable with a final light finishing pass. For parts beyond Swiss-turn size range or with complex milled features, 4-axis CNC turning centers handle brass up to 6 inch diameter while maintaining similar tolerance capability on turned features.
Lead-free brass grades — bismuth brass C89520, silicon brass C87600, and others — are available from regional service centers but in narrower size ranges and less consistent stock depth than C360. Procurement lead times for lead-free brass bar stock run 1 to 2 weeks longer than C360 for uncommon sizes, which adds to prototype and bridge-production lead times for new programs. Cutting speeds and feeds must be adjusted for lead-free grades: machinability indexes of 70 to 80 versus C360's 100 mean cycle times are 20 to 30 percent longer, which reflects in piece price. Tool wear is somewhat higher, and thread quality requires more attention to toolpath and insert sharpness. The overall cost premium for lead-free brass machined parts compared to equivalent C360 parts runs 15 to 35 percent depending on part complexity. Buyers should factor this into program cost models from the start, rather than discovering it after a C360 program must be re-sourced for regulatory compliance.
Janesville-area brass fabricators and their finishing sub-tiers offer the full range of brass surface treatments standard in industrial and automotive supply chains. Tin plating per ASTM B545 — bright or matte, 0.0003 to 0.001 inch — is the most common treatment for automotive electrical connector and terminal applications, providing oxidation resistance and reliable solderability. Nickel plating (electrolytic bright nickel or semi-bright per ASTM B689) is used for wear-resistant surfaces, decorative finishes, and as an undercoat beneath tin for improved corrosion performance in harsh environments. Electroless nickel provides uniform coverage on complex geometries including blind holes and recessed features where electroplating builds unevenly. Chromate conversion coating (clear or yellow) provides light corrosion protection without significant dimensional buildup — important on tight-tolerance features. Passivation is not applicable to brass as it is to stainless steel. Buyers should specify the finish standard, thickness range, and any adhesion or salt-spray requirements (ASTM B117 hours) on the drawing rather than using generic finish callouts that leave interpretation open.
Last updated: July 2026
Find Brass Manufacturers in Janesville, WI
Search verified Janesville shops that work in Brass.
No logins. No email gates. Just results.