Engineering · Machining guide
How to machine brass C360.
Brass C360 is the machinability benchmark for copper alloys — it is the 100 reference on the copper-alloy scale, and other brasses and bronzes are rated against it. Lead alloying produces tiny lubricating particles in the chip, eliminating built-up edge and giving exceptional surface finish from standard tooling. Almost any cutting parameter works. The complications are environmental: lead content rules out some medical, food-contact, and DOD applications.
01 · Cutting parameters
Almost anything works — but here's optimal.
| Operation | Tool | SFM | IPT / IPR |
|---|---|---|---|
| Roughing turn | Uncoated carbide | 500–1000 | 0.010–0.020 IPR |
| Finishing turn | Uncoated carbide | 600–1200 | 0.005–0.012 IPR |
| End mill (rough) | Solid carbide 3FL | 500–900 | 0.005–0.010 IPT |
| End mill (finish) | Solid carbide 3FL | 800–1200 | 0.003–0.007 IPT |
| Drilling | HSS or carbide | 200–400 | 0.005–0.012 IPR |
| Tapping | HSS | 60–120 | — |
| Reaming | HSS or carbide | 100–200 | 0.003–0.008 IPR |
IPT (chip-load) values assume roughly ½–1″ end mills; scale down for smaller tools — see the chip-load chart.
02 · Practical notes
Lead is the only complication.
- Tooling: standard uncoated carbide or HSS. Polished flutes preferred for surface finish. C360’s short broken chips don’t pack the way copper or aluminum do.
- Coolant: water-soluble flood, MQL, or dry. Brass tolerates almost anything.
- Lead content (~3%): ruled out for many medical, food-contact, and pediatric-toy applications. The limit that usually bites is drinking water: NSF/ANSI 61/372 caps wetted surfaces at 0.25% lead (weighted average). EU RoHS exemption 6(c) still permits up to 4% lead in copper alloys (check the exemption’s current status for your product category), and California Prop 65 may require a warning. For lead-sensitive applications, consider low-lead alternatives (C46500 bar, or EnviroBrass C89510 / C89520 / C89550 castings) — slower machining.
- Common applications: plumbing fittings, decorative hardware, electrical connectors, instrument housings, valve trim. Swiss-type production runs in C360 are routine on our Tsugami.
- For aerospace small-diameter precision: C360 is excellent for electrical connector pins and small-bore fittings. AS9100 traceability flows through normally — chemical certs available from major mills.
- Surface finish: 16 µin Ra easily achievable with standard inserts. 8 µin Ra possible with sharp PCD or polished carbide.
Keep exploring
Related tools & references
Full mechanical, thermal, and chemical properties.
Dial in SFM and IPT for C360's high cutting speeds.
Per-tooth chip loads for brass and free-machining alloys.
8.50 g/cc — weigh up finished parts and stock.
Compare C360 against lead-free brass alternatives.
Technically reviewed by the True Precision Machining engineering team · Last reviewed June 2026
Standards referenced: ASTM B16
Need brass C360 parts machined?
Send your drawing — brass C360 is a material we run regularly. Aerospace, medical, and defense work welcome.
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