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. C360 is also a common Swiss-type turning material.
- 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.
Need brass C360 parts machined?
Tell us about your part and we'll get back to you promptly. Aerospace, medical, defense, and semiconductor production work welcome.Email CAD models and drawings to sales@digitalmachine.com, including ITAR, EAR, CUI and AS9100 work. Keep controlled technical data out of web forms.
First articles through full production runs