Brass vs bronze: which copper alloy for your part?
Brass vs bronze for machined parts: the composition difference, machinability, corrosion and wear, cost, and when to spec each one.
Brass is copper and zinc; bronze is copper and tin (plus others). Brass machines beautifully and is cheaper, so it wins for fittings, fasteners, valves and decorative parts. Bronze is harder, stronger and far better in wear and marine corrosion, so it wins for bushings, bearings, gears and anything in seawater. If the part slides, carries a load, or lives in salt water, spec bronze. If it is a fitting or a turned part machined in volume, brass is usually the right and cheaper call.
The actual difference
Brass is a copper-zinc alloy. Bronze is a copper-tin alloy, often with aluminum, silicon or phosphorus added for specific properties. That one change (zinc versus tin) is why their behavior diverges on wear, corrosion and cost.
| Property | Brass (Cu-Zn) | Bronze (Cu-Sn) |
|---|---|---|
| Machinability | Excellent (free-machining C360 is the benchmark) | Good, harder on tools |
| Strength and hardness | Moderate | Higher |
| Wear / bearing performance | Fair | Excellent (the classic bushing material) |
| Corrosion (marine) | Can dezincify in seawater | Very good, the marine choice |
| Cost | Lower | Higher |
| Typical use | Fittings, valves, fasteners, decorative | Bushings, bearings, gears, marine hardware |
When to spec brass
Fittings, valve bodies, plumbing and gas components, electrical terminals, instrument parts, and anything turned in volume. Free-machining brass (C360) is one of the fastest, cleanest metals to cut, so unit costs drop hard at quantity. Brass also takes plating and polishing well for decorative work.
When to spec bronze
Anywhere there is sliding contact or load: sleeve bearings and bushings (bronze is the default), worm gears, thrust washers, and valve seats. And anywhere there is salt: marine hardware, propeller and pump components, and fittings that would dezincify in brass. Phosphor bronze for springs and bearings, aluminum bronze for high strength and corrosion, silicon bronze for weldability.
Dezincification: the brass failure mode
In seawater and some aggressive waters, ordinary brass loses its zinc and turns porous and weak. That is why bronze, or a dezincification-resistant brass, is specified for marine and some potable-water parts. If your brass part sees chlorides, raise it with the shop before you commit.
What to send for a quote
The part, the alloy if you know it (C360 brass, C932 bearing bronze, and so on) or the function (sliding, marine, decorative) and we will flag the grade. Quantity matters more here than most materials because brass is so fast to machine. Request quotes from Canadian shops that machine copper alloys daily.
FAQ
What is the difference between brass and bronze?
Brass is copper alloyed with zinc; bronze is copper alloyed with tin (and sometimes aluminum or silicon). Brass machines faster and costs less; bronze is harder and better for wear and marine corrosion.
Is bronze stronger than brass?
Generally yes. Most bronzes are harder and stronger than most brasses, which is why bronze is used for bearings, gears and high-load parts.
Which is better for marine parts, brass or bronze?
Bronze. Ordinary brass can dezincify in seawater and go porous, while bronze (or a dezincification-resistant brass) holds up. Spec bronze for anything in salt water.
Which machines more easily?
Brass, especially free-machining C360, is one of the most machinable metals there is. Bronze machines well but is harder on tooling.
Is brass or bronze more expensive?
Bronze is usually more expensive because tin costs more than zinc and bronze alloys are harder to process. For high-volume turned parts, brass is the economical choice.
Last reviewed: October 2026. Related reading: 304 vs 316 stainless steel and 6061 vs 7075 aluminum.
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