Plain Bearings: Bronze vs. Brass vs. Copper – Which Is Best? Brass Composition

Plain bearings—also known as bushings or sleeve bearings—are simple, non-rolling bearings that reduce friction between moving parts. The choice of bronze, brass, or copper as the bearing material greatly affects performance, durability, and cost.

This guide explains the differences between bronze, brass, and copper bearings, the composition of brass alloys, and how to choose the right material for your application.

1. Differences Between Bronze, Brass, and Copper

2. Brass Composition

Brass is mainly an alloy of copper and zinc, with possible additions to improve performance:

• Copper (Cu): 60–80%

• Zinc (Zn): 20–40%

• Optional Additives:

  • Lead (Pb): Up to 3% for machinability (free-cutting brass).

  • Tin (Sn): ~1% for better corrosion resistance (naval brass).

  • Iron, Aluminum, or Silicon: Trace amounts for strength or special properties.

Common Brass Alloys for Bearings:

• C36000 (Free-Cutting Brass): 61.5% Cu, 35.5% Zn, 3% Pb; excellent machinability.

• C46400 (Naval Brass): 60% Cu, 39% Zn, 1% Sn; great for marine environments.

• ⚠️ Note: C93200 is actually a bronze (tin-based), though it’s sometimes mistaken for brass.

3. How to Choose the Right Material

✅ Choose Bronze when:

• High load, low speed – Ideal for heavy-duty machinery, pumps, turbines, or construction equipment.

• Corrosive environments – Best for marine or chemical exposure.

• Long service life – Superior wear resistance ensures durability.

Example: Bushings in pumps, valves, and heavy equipment.

✅ Choose Brass when:

• Moderate load and speed – Good for small motors, fittings, or lighter-duty bearings.

• Cost-sensitive applications – More affordable than bronze.

• Easy machinability – Perfect for custom components or precision fittings.

Example: Bearings in appliances, plumbing fixtures, or low-load gears.

⚠️ Choose Copper only when:

• Electrical conductivity is essential.

• Non-bearing applications – Suitable for connectors, sleeves, or decorative parts, but not load-bearing bearings.

Example: Electrical contacts or conductive sleeves.

4. Key Considerations

• Load & Speed:

  • Bronze → high load / low speed

  • Brass → moderate load / moderate speed

  • Copper → unsuitable for most bearings

• Lubrication:

  • Bronze often runs well with minimal lubrication.

  • Brass and copper need consistent lubrication.

• Environment:

  • Bronze → harsh, corrosive, marine conditions

  • Brass → general-purpose, less demanding conditions

  • Copper → electrical and decorative uses

• Budget:

  • Bronze is premium (best performance).

  • Brass balances cost and performance.

  • Copper is cheapest, but rarely practical for bearings.

5. Recommendation

• Bronze is the best all-around choice for plain bearings, offering strength, wear resistance, and corrosion protection in demanding environments.

• Brass is a budget-friendly compromise, suitable for lighter-duty, cost-sensitive applications.

• Copper is rarely used for bearings but remains useful in electrical or specialty non-load applications.

👉 If you need help selecting the right alloy for your bearing application, consider factors like load, speed, environment, and lubrication.