Brass vs bronze is a common question on fittings, bushings, bearings and marine hardware. Both are copper alloys. Brass is primarily copper and zinc and is valued for machinability, appearance and moderate corrosion resistance. Bronze is primarily copper with tin, aluminum or other elements and is valued for wear resistance, strength and resistance to seawater. Free-machining brass is one of the fastest materials to machine, while bronzes are chosen when the part must carry load or slide against another surface.
Brass vs Bronze: Comparison Table
Values are typical. Cost is a relative per-part index including material, where one C360 brass part at quantity 1 equals 100.
| Factor | Free-machining brass (C360) | Bearing bronze (C932) | Aluminum bronze (C954) |
|---|---|---|---|
| Relative cost, qty 1 | 100 | 110 to 125 | 120 to 140 |
| Relative cost, qty 10 | 38 | 45 to 55 | 52 to 62 |
| Relative cost, qty 100 | 15 | 20 to 26 | 25 to 32 |
| Relative cost, qty 1,000 | 8 | 13 to 17 | 17 to 22 |
| Machinability rating | 100 (the reference) | About 70 | About 60 |
| Tensile strength | About 50 to 60 ksi | About 35 ksi | About 85 ksi |
| Wear and bearing performance | Fair | Very good, conformable | Very good under high load |
| Typical machined tolerance | ±0.0005 to ±0.002 in | ±0.001 to ±0.002 in | ±0.001 to ±0.003 in |
| Surface finish | Ra 16 to 32 µin readily | Ra 32 to 63 µin | Ra 32 to 63 µin |
| Corrosion | Good in fresh water; dezincification possible | Good | Excellent, including seawater |
| Lead time | Widely stocked bar | Stocked as cored and solid bar | Stocked in common sizes |
| Typical use case | Fittings, valves, electrical parts, decorative hardware | Bushings, bearings, thrust washers | Heavy-duty bushings, gears, marine and valve parts |
When Brass Wins
- High-volume turned parts. C360 is the machinability benchmark. It runs fast on Swiss and bar-fed lathes with excellent finish.
- Fittings and valve components. Good sealing surfaces, easy threads and reasonable corrosion resistance.
- Electrical parts. Good conductivity with easy machining.
- Appearance. Bright gold color for visible hardware.
When Bronze Wins
- Bushings and bearings. Bearing bronzes such as C932 (SAE 660) conform to shafts and resist galling.
- High loads. Aluminum bronzes such as C954 are much stronger and handle heavy, slow-moving loads.
- Seawater. Aluminum and nickel-aluminum bronzes resist seawater far better than brass.
- Anti-galling pairs. Bronze against steel is a classic sliding combination.
Common Mistakes
- Using brass for bushings under load. It wears and galls faster than bearing bronze.
- Specifying leaded brass for potable water. Lead-free alloys such as C69300 are used where drinking water rules apply.
- Calling out "bronze" without an alloy number. Tin, aluminum and silicon bronzes behave very differently.
- Using yellow brass in seawater, where dezincification can weaken the part over time.
Machining Notes
Free-machining brass produces small, broken chips and runs at high speeds. Bearing bronzes machine well but can smear if tools are dull. Aluminum bronze is tougher and closer to a steel in behavior. Bushings typically need controlled bore size and wall concentricity, which is lathe work and routine on Swiss-type machines for smaller sizes.
How This Applies at Wexmar
Wexmar machines brass, bronze and copper on our CNC lathes and Maier Swiss-type machines, which handle small brass fittings and bronze bushings to 32 mm diameter efficiently. Larger bushings and flanged parts run on our conventional lathes with live tooling. See Swiss machining, materials, and the guide on Swiss vs CNC lathe.
Getting a Quote
Include the alloy number on your drawing. You can upload a drawing for an instant estimate, confirmed by a human estimator, or call (315) 400-2654.