CU · copper alloy
Aluminium Bronze C95400 (UNS C95400)
Roughly twice the strength of a tin bronze and harder to machine than it looks on a datasheet. It work-hardens, it is abrasive, and the cutting speeds are closer to stainless than to brass.
Quoting this material
- Typical lead time
- 10–18 working days
- Condition
- Cast, or wrought in similar compositions
- Achievable finish
- Ra 1.6 µm typical · Ra 0.8 µm best
Machined in-house to your drawing: see the precision CNC machining service and the machine and inspection capability it runs on.
Machinability
Our own 1–10 shop ranking, not a published index: 10 is free-cutting brass C360, 1 is Inconel 718. It ranks how a material behaves on the floor - cycle time, chip control and tool life together. Where a published index exists it is quoted in the note.
Roughly twice the strength of a tin bronze and harder to machine than it looks on a datasheet. It work-hardens, it is abrasive, and the cutting speeds are closer to stainless than to brass.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 585 | MPa |
| Yield strength (0.2%) | 240 | MPa |
| Elongation | 12 | % |
| Hardness | 170 | HB |
| Thermal conductivity | 59 | W/m·K |
| Modulus of elasticity | 110 | GPa |
Hardness, tensile and thermal figures are typical published values for the condition stated. Actual mill certificates govern; send the specification with the drawing and we confirm against the certificate before the material is cut.
Condition
Cast, or wrought in similar compositions
Heat treatment
Can be heat treated in some grades to refine the structure, but the standard 954 condition is cast and used as-is. It is a bearing and wear alloy, not a heat-treatable one.
Achievable surface finish
Ra 1.6 µm
Ra 0.8 µm
Finish is workable but the material smears if the tool is dull; a sharp, positive tool is the difference.
Tooling and cutting parameters
Cutting speed
- 80–150 m/min (carbide)
Feed
- 0.10–0.25 mm/rev turning · 0.06–0.15 mm/tooth milling
Tooling
- Uncoated or coated carbide, sharp positive rake, rigid setup
Coolant
- Flood
Starting points for carbide on a rigid setup, not a guarantee. The right numbers depend on the machine, the toolholder and the fixturing - ask and we will say what we would actually run.
Typical applications
- Heavy-duty bushings and bearings
- Worm wheels and gear blanks
- Valve seats and guides
- Pump impellers and casings
- Marine and offshore wear parts
DFM notes for this grade
- In a worm gear pair the aluminium bronze wheel must run against a hardened steel worm - an unhardened worm will wear instead of the wheel and the whole advantage is lost
- It is notch sensitive in the cast condition: sharp internal corners in a highly loaded bearing are crack sites
- Roughly twice the cost of tin bronze and harder to machine; use it where the load actually requires it rather than as a general upgrade
Questions buyers ask
- When is aluminium bronze worth twice the price of tin bronze?
- When the load is high and the speed is low, or when the environment corrodes tin bronze. Aluminium bronze carries roughly twice the load and resists seawater, which is why marine propeller hardware and heavy worm wheels use it.
- Why does it machine so much harder than brass?
- Aluminium in solid solution hardens the copper matrix and the material work-hardens quickly. The cutting speeds drop by more than half, the tool wears faster and the chips are tough rather than brittle - everything that makes brass pleasant is absent.
Grades we would quote instead
C93200 Bearing Bronze
6/10The standard bearing bronze: it machines well, it is soft enough to embed grit, and it runs against a steel shaft without galling.
C63000 Nickel Aluminium Bronze
4/10The strongest of the standard bronze families: about the cutting speed of a stainless and the tool wear of one too.
C51000 Phosphor Bronze
6/10The spring bronze: good machinability with enough tin to give real strength and fatigue resistance.