For a loaded, wearing bushing, bronze is the right metal — phosphor bronze (C51000) for general high-load use, aluminium bronze for the heaviest, most abrasive and marine duty. Its higher hardness, strength and wear resistance give longer bearing life. Brass wins only when loads and speeds are low, or when the part is really an electrical component that happens to slide, and where cost and machinability dominate — free-cutting brass sits at 100 on the copper-alloy machinability scale against roughly 20 for phosphor bronze, so a bronze bushing costs meaningfully more in both material and machine time.
This is a bearing-performance comparison, not a general "which alloy is better". For plain bearings and bushings the real contest is phosphor bronze or aluminium bronze versus leaded brass. Bronze is the traditional bearing metal; brass competes on cost and machinability for lighter-duty and electrical roles.
A rare case where one ruler covers both sides
Bronze machinability is quoted on the same copper-alloy scale as brass (C36000 = 100), so the machinability figures in this post are directly comparable — unlike the brass-versus-stainless or brass-versus-aluminium cases, where different scales apply.
Brass vs bronze: the numbers side by side
| Property | Leaded brass (C36000 / CW614N) | Phosphor bronze C51000 / CW451K (CuSn5) | Aluminium bronze (e.g. C63000-class) |
|---|---|---|---|
| Machinability (copper-alloy scale) | 100 | ~20 | Low (~20–30, varies by grade) |
| Ultimate tensile strength (MPa) | ~330–530 | ~450–620 | Higher still (heavy grades 620–830+) |
| Hardness (HB) | Lower | ~90–150 HB | Higher |
| Wear resistance (bearing) | Moderate — OK for light / low-speed | High — phosphorus raises wear resistance & stiffness | Very high — heavy-load / abrasive |
| Load capacity | Low–medium loads | High loads / speeds | Highest — heavy, shock, high load |
| Self-lubrication | Limited | Good; base for oil-impregnated & graphite-plugged bushes | Good; used with solid-lubricant inserts |
| Marine / seawater corrosion | Good (DZR grades better) | Excellent atmospheric & marine | Excellent — a premier marine bearing metal |
| Relative cost | Lowest (cheapest to buy and to machine) | Higher (tin content + slower machining) | Highest of the three |
| Best-fit role | Light-duty bushes, electrical / low-load, high-volume machined parts | General-purpose high-load bushings, springs, bearings | Heavy-load, marine, shock / abrasion bearings |
Reading the machinability gap: brass at 100 against phosphor bronze at around 20 is the single biggest practical difference. Phosphor bronze is roughly five times slower and harder to machine, so a bronze bushing costs more in both material and machine time — that is the price you pay for its bearing performance. As a rule of thumb from the trade, brass can be run about 20 to 30 percent faster than typical bronzes on comparable work.
When each wins (honest)
Bronze wins for actual bearing duty
Higher load, higher sliding speed, better wear resistance and a lower, more stable friction coefficient. Phosphor bronze (C51000) is the general-purpose high-load bushing, bearing and spring metal; aluminium bronze steps up for the heaviest loads, shock, abrasion and demanding marine service. Bronze is also the base for self-lubricating oil-impregnated and graphite-plugged bushes. If the bushing is doing real bearing work, this is your material.
Brass wins on cost and machinability
For light-duty, low-speed or non-critical bushings, and where the part is really an electrical or conductive component that happens to slide, or a high-volume machined part where bronze's roughly five-times machining penalty is not justified. For a lightly loaded bushing made in quantity, leaded brass is often the economical, good-enough choice. The trade-off is lower load capacity and wear life.
How Brassland fits in
We machine brass, copper and aluminium — including leaded free-machining CW614N for light-duty bushes and sliding electrical parts. For a lightly loaded or electrical bushing made in volume, brass is often the sensible pick, and we will turn it to tolerance on our Swiss and CNC machines. If your bushing carries real bearing load or lives in seawater, bronze is the safer material — do not substitute brass for bronze on cost alone.
Frequently asked questions
Is bronze or brass better for a bushing?
Why is bronze more expensive to machine than brass?
Which is better in seawater, brass or bronze?
Can brass ever replace a bronze bushing?
What is the difference between phosphor bronze and aluminium bronze for bearings?
Sources & references
Figures on this page are drawn from published alloy datasheets, standards bodies and engineering references. Key sources:
Last reviewed: July 2026. Material and process figures are checked against datasheet and standards references at each review. Cross-material machinability numbers are indicative (see note in the article), not two points on one physical scale.
Need this part in the right alloy?
Brassland machines precision brass, copper and aluminium components to your drawing — Swiss turning to ±0.005 mm, CNC machining in-house, and hot forging through qualified partners. Send a drawing and we will get back to you.
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