Brass CNC Machining Services
C36000 free-cutting brass is the 100 percent reference against which every other copper alloy is rated, giving the fastest cycle times and best surface finish of any metal we machine.
C36000, C26000 and lead-free brass grades
Tolerances to ±0.02 mm on turned parts
Plating, passivation and polishing available
What Is Brass?
Why brass is the cheapest metal to machine per part, and where its lead content rules it out.
C36000, known as free-cutting brass or 360 brass, contains about 61.5 percent copper, 35.5 percent zinc and 3 percent lead. The lead acts as an internal chip breaker, so the alloy shears cleanly instead of forming long ribbons. It is the reference against which the machinability of every other copper alloy is rated at 100 percent, and in practice it machines faster than free-cutting steel.
What that means for cost
On a screw machine or a CNC lathe, brass runs at very high spindle speeds with excellent surface finish and long tool life. Cycle times drop, tooling cost drops, and secondary deburring is often unnecessary. For high-volume turned parts, fittings and connectors, brass frequently beats aluminium on total part cost despite the higher material price.
Compliance limits to check
The lead content puts C36000 under RoHS exemption 6(c) and rules it out of potable water systems under NSF and ANSI 372, which limits weighted lead to 0.25 percent. If your part touches drinking water or needs a full RoHS declaration, ask us about lead-free alternatives such as bismuth brass grades with roughly 90 percent of the machinability.
Related capabilities: CNC Machining, CNC Milling, CNC Turning, 5-Axis Machining. Dimensional limits, thread rules and surface roughness grades are listed on the tolerances and specifications page, and volume-based routing is covered under production solutions.
Brass Mechanical Properties
Typical values at room temperature for the condition most often machined. Use them for material screening, then confirm against the mill certificate for the exact heat and product form.
| Property | Typical value |
|---|---|
| Density | 8.50 g/cm³ |
| Ultimate tensile strength | 380 MPa (55 ksi) |
| Tensile yield strength, 0.5% extension | 305 MPa (44 ksi) |
| Elongation at break | 25 to 32% in 50 mm |
| Elastic modulus | 97 GPa |
| Hardness | 75 HRB |
| Shear strength | 220 MPa |
| Thermal conductivity | 115 W/m·K |
| Electrical conductivity | 26% IACS |
| Melting range | 885 to 900 °C |
Typical room-temperature values compiled from public ASM, MatWeb and mill datasheets. Actual values vary with temper, section thickness and product form; request the EN 10204 3.1 certificate for critical applications.
Machining Characteristics of Brass
How the material behaves in the cut, and what that means for tooling, fixtures, cycle time and achievable tolerance.
Fastest cycle times
C36000 is the machinability benchmark at 100 percent. Spindle speeds can be pushed far higher than with steel or stainless without sacrificing finish.
Self-breaking chips
Lead dispersions break the chip into small segments, so long swarf rarely wraps around the part, the tool or the chuck.
Excellent surface finish
As-machined brass commonly reaches Ra 0.8 µm or better, which removes a polishing operation for many decorative and sealing faces.
Great for threads and knurling
Roll threading and knurling work well, and the alloy holds a crisp thread form without tearing.
Low ductility for forming
High-lead brass is not suited to bending, staking or heavy cold work. Use C26000 cartridge brass for formed parts instead.
Lead-free options
Bismuth and silicon brass grades are available for potable water and full RoHS compliance, trading roughly 10 percent of the machinability.
Design and Machining Checklist
Practical rules that reduce cost and scrap on Brass parts. Share them with your design team before the drawing is frozen.
- Use brass for high-volume turned parts where cycle time dominates the part cost.
- Do not specify C36000 for potable water contact; choose a lead-free bismuth or silicon brass.
- Sharp tools still matter: a dull edge smears the lead phase and produces a poor surface on sealing faces.
- Avoid designs requiring bending or staking; high-lead brass cracks under forming.
- Allow for dezincification in aggressive water by specifying a dezincification-resistant grade where needed.
- Nickel or chrome plating is the standard route to a decorative, tarnish-resistant finish.
Surface Finishing Options
Finishes are selected for corrosion resistance, wear, appearance, electrical behaviour or cleanliness. Specify only what the function needs.
As-Machined
Ra 0.8 to 1.6 µm, bright and clean. Often the final finish for internal components and fittings.
Nickel Plating
5 to 25 µm electrolytic nickel for corrosion resistance, solderability and a bright silver appearance.
Chrome Plating
Hard, wear-resistant decorative layer used on consumer hardware, taps and visible trim.
Passivation and Anti-tarnish
Benzotriazole or lacquer coating that slows surface oxidation on parts that must keep their colour in storage.
Polishing and Buffing
Mechanical bright polish to a mirror finish for decorative fittings, nameplates and architectural hardware.
Tin Plating
Food-safe and solderable coating used for electrical contacts and potable water components.
Typical Applications
Where Brass is most often specified, and why it wins against the alternatives.
Fluid fittings and valves
Compression fittings, unions, adaptors, plugs and valve bodies for air, gas, fuel and non-potable water.
Electrical connectors and terminals
Pins, sockets, busbar connectors and contact bodies that combine 26 percent IACS conductivity with good machinability.
Fasteners and inserts
Nuts, standoffs, threaded inserts, set screws and spacers produced at high volume on automatic lathes.
Sensor and instrument bodies
Housings, gauge bodies, meter components and pressure fittings requiring stable dimensions.
Plumbing hardware
Non-potable valve cartridges, faucet bodies and pipe fittings where lead content is permitted by local code.
Gears and small mechanisms
Pinions, cams and precision mechanism parts where low friction and dimensional stability matter.
Need Brass parts quoted?
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