Brass CNC Machining
C36000 free-machining brass parts to ±0.001 in — from electrical connectors to valve parts, single prototypes to high-volume production.
The Fastest-Cutting Metal on Our Floor
Brass is the machinist's favorite metal: it cuts faster than anything else we run, produces clean broken chips, holds excellent tolerances, and needs no coolant drama. Add natural corrosion resistance, good electrical conductivity, and an attractive finish, and you get the default material for connectors, fittings, valves, and decorative hardware. IsoCNC runs brass CNC machining across turning, Swiss turning, and milling, from single prototypes to high-volume production of brass machined parts for North American and European OEMs.
Brass Grades We Machine
- C36000 (free-machining brass) — the industry standard, with a machinability rating of 100 (the benchmark all other metals are rated against). Lead content makes chips break cleanly and tools last. Covers most fittings, connectors, and turned hardware. Note: not suitable for potable-water or RoHS-restricted applications
- C27400 / C27200 (yellow brass) — good all-around machinability with lower lead content
- C38500 (architectural bronze) — for decorative and architectural hardware
- C46400 (naval brass) — superior corrosion resistance in marine environments
- Lead-free brass (e.g. C69300) — for potable water and regulatory-compliant parts; machines well but slower than C36000
If your drawing just says "brass," we will quote C36000 — it is the cheapest and fastest option. Tell us if lead content is restricted, and we will route you to a compliant grade.
Machinability and How We Cut It
C36000 cuts roughly three times faster than mild steel and about twice as fast as 6061 aluminum on many operations. Our approach:
- High-speed turning and milling — carbide tooling at aggressive speeds and feeds; most brass work runs on CNC turning, with live-tooling for cross-holes and flats in one setup
- Swiss for small, long, or high-volume parts — pins, contacts, and slender shafts under 32 mm diameter run on Swiss CNC machining, where the guide bushing supports the cut and unattended running keeps piece prices low
- Chip control is built in — leaded brass breaks into short, manageable chips with no stringers, so cycle times stay low and lights-out running is practical on production volumes
- Deburring as standard — brass is soft and edges burr easily on cross-holes and threads; every part gets tumbling or hand deburring so fittings assemble cleanly
- Threads and sealing surfaces — we cut NPT, BSP, and metric threads daily, with finishing passes on sealing faces to Ra 0.8 µm (32 µin) where your drawing calls for it
Tolerances and Surface Finishes
General milled and turned features hold ±0.005 in (±0.13 mm); critical bores, threads, and sealing surfaces to ±0.001 in (±0.025 mm) quoted against the drawing. Brass holds tolerance exceptionally well because cutting forces are low and there's no built-up edge.
As-machined finish is Ra 3.2 µm (125 µin) standard, and brass takes a beautiful machined finish that many customers use as-is. Where corrosion protection or appearance matters, brass accepts nickel plating, chrome plating, tin plating (for electrical contact), powder coat, and clear coatings to prevent tarnish. See surface finishes for the full range.
Typical Brass Parts
Electrical connectors and terminals, RF and coaxial components, plumbing and pneumatic fittings, valve bodies and stems, nozzles, threaded inserts for plastic molding, gears, decorative hardware, and musical-instrument components. Brass's conductivity makes it a common alternative where pure copper machining would be slower and more expensive — you give up some conductivity and gain a material that holds threads, knurls, and fine detail without tearing.
Brass Machining — Capability Summary
| Capability | Specification |
|---|---|
| Grades in stock | C36000, C27400, C38500, C46400, lead-free C69300 (others on request) |
| General tolerance | ±0.005 in (±0.13 mm); precision features to ±0.001 in (±0.025 mm) |
| Threads | NPT, BSP, metric; internal and external |
| As-machined finish | Ra 3.2 µm (125 µin); to Ra 0.8 µm (32 µin) on sealing surfaces |
| Finishes | As-machined, nickel/chrome/tin plating, powder coat, clear coat, tumbling |
| Batch range | 1 pc prototype to high-volume production |
| Typical lead time | Prototypes from 3 days; production typically 2–3 weeks |
Drawing Tips for Brass Parts
- Call the grade, or say “free-machining brass.” An unspecified “brass” gets quoted as C36000 — the right answer for cost, but a problem if your application restricts lead.
- Flag plating thickness on threads and fits. Nickel or chrome adds measurable build; either tolerance the plated dimension or note “dimensions after plating” so we machine with the allowance built in.
- Don’t over-tolerance non-functional faces. Brass machines so cleanly that ±0.001 in is achievable almost anywhere — but inspecting it everywhere costs more than the material saves. Tight-tolerance the bores and threads; let cosmetic faces run at general tolerance.
- Small turned parts: send the annual volume. A part that is expensive as a one-off milling job can be nearly free as a Swiss-turned production part; the quantity changes the process recommendation.
Quote Your Brass Parts
Send STEP files and drawings — note any lead-content or plating requirements, and we'll return pricing, lead time, and DFM feedback within 1–2 business days. For other metals and plastics, see the full materials page.
Quote Your Brass Parts
Send STEP files and drawings — note any lead-content or plating requirements, and we'll return pricing, lead time, and DFM feedback within 1–2 business days.
Get an Instant Quote →