How to Choose a Bronze Bushing Material: C93200 vs C93700 vs C95400

The short version: C93200 for everyday bearings, C93700 where dirt and poor lubrication are normal, C95400 where loads exceed what tin bronzes carry, C86300 when high load and wear dominate, and C95800 for seawater and erosion-corrosion.

Why lead is in bearing bronze

The classic bearing bronze recipe is copper plus tin plus lead. Tin hardens the alloy; lead does something subtler — it exists as soft particles that act like a dry lubricant and, more importantly, let grit bury itself instead of cutting the shaft. A bushing carrying dust and shock loads without lead in it soon becomes a shaft-scoring machine.

That trade-off matters more than the strength numbers when you are choosing.

C93200 (SAE 660) — the default

Copper 81–85%, tin 6.3–7.5%, lead 6–8%, zinc 4–7%. It is the most common bearing bronze in the world: strong enough for the vast majority of industrial bushings, easy to machine, and its lead content swallows ordinary levels of contamination. If you are replacing a bushing and nobody specified an alloy, C93200 is the safe default. See the C93200 material data.

C93700 — for the dirtiest jobs

The lead climbs to 9–12% and tin to 9–11%. More lead means more embeddability and better seizure resistance under shock and boundary lubrication; it costs strength and machinability. This is the alloy for crusher socket liners and mining bushings where oil is marginal and grit is everywhere. See the C93700 material data.

C95400 — when the load wins

Aluminum bronze: copper 83–87%, aluminum 10–11.5%, iron 3–4.5%. Roughly twice the strength of tin bronzes, seawater corrosion resistance, and it keeps strength at elevated temperature. It is harder, so it needs reasonably clean, aligned, lubricated service — put it where tin bronze would break, not where it would wear. See the C95400 material data.

C86300 — when load and wear dominate

Manganese bronze is a high-strength, wear-resistant grade for high-load, low-speed bearings, wear plates, nuts and worm-wheel applications. It is harder and less forgiving of misalignment or dirty lubrication than C93200 or C93700, so choose it when the duty is load and abrasion, not when embedding is the priority. See the C86300 material data.

C95800 — for seawater and erosion-corrosion

Nickel-aluminum bronze combines high mechanical strength with excellent resistance to seawater corrosion and erosion-corrosion. It is used for marine pump and valve bushings, impellers and heavy-duty fittings. It is harder and higher cost than C93200, and it is not a dry-running alloy — select it for wet, corrosive duty. See the C95800 material data.

A simple decision path

Dirty service, marginal lubrication → C93700. Normal industrial service → C93200. High load, hot or seawater → C95400. High load, low speed and wear → C86300. Seawater and erosion-corrosion → C95800. When in doubt, send us the duty: load, speed, lubrication, environment, and a drawing or sample. We cast these grades daily and will recommend the one that survives.

Alloy data at a glance: C93200 tin bronze, C93700 lead bronze, C95400 aluminum bronze, C86300 manganese bronze, C95800 nickel-aluminum bronze — compositions, key properties and typical applications.

For a deeper C86300 vs C95400 comparison, read Manganese Bronze vs Aluminum Bronze. To discuss a specific bushing, request a quote.