Aluminum bronze is a family of copper alloys in which aluminum is the main alloying element. Iron, nickel and manganese may also be added to change strength, wear resistance, corrosion resistance and casting performance. These alloys are used for bushings, gears, wear parts, pumps and valves. “Aluminium bronze” is the British spelling of the same material family.
What Is Aluminum Bronze Made Of?
Aluminum bronze consists mainly of copper and aluminum. Across the wider family, aluminum content is often about 5% to 12%, although many industrial cast grades contain approximately 8.5% to 11.5%. Aluminum content alone does not determine performance.
Other alloying elements may be added for specific purposes:
| Element | General effect in the alloy |
|---|---|
| Aluminum | Increases strength and hardness and helps form a protective oxide layer |
| Iron | Supports strength, wear performance and grain refinement |
| Nickel | Improves mechanical strength and corrosion resistance in demanding environments |
| Manganese | Supports strength and deoxidation in selected grades |
Aluminum bronze is therefore not one fixed material. A drawing should specify a full grade and standard rather than state only “bronze” or “aluminum bronze.” For an overview of the larger material family, see What Is a Copper Alloy?
Aluminum Bronze Properties and Limitations
Industrial aluminum bronze grades can provide high strength, hardness, wear resistance and resistance to deformation. They are often considered for loaded parts exposed to impact, repeated movement or moisture. Nickel aluminum bronze grades are also used for selected marine components.
However, aluminum bronze is not automatically the best material for every bushing or wear part. Important limitations include:
- Machining requirements: Some grades are harder to machine than common bearing bronzes.
- Shaft compatibility: A hard bushing can damage a softer shaft if hardness, finish and clearance are unsuitable.
- Lubrication: High strength does not remove the need for correct lubrication, groove design and operating clearance.
- Casting control: Oxidation, shrinkage, feeding and section thickness must be controlled during production.
- Environmental differences: Not every aluminum bronze grade has the same resistance to seawater, chemicals or elevated temperature.
Compared with tin bronze, aluminum bronze is often considered when higher strength, impact resistance or corrosion resistance is required. Tin bronze may be preferred for other sliding, bearing or gear applications. The final choice depends on the grade and working condition, not only the alloy family.
Main Types and Common Aluminum Bronze Grades
Cast aluminum bronzes include copper-aluminum-iron alloys and nickel aluminum bronze alloys. Wrought grades are produced as bars, plates, forgings or other worked forms and should not be treated as identical to cast grades with similar names.
The following table shows common cast grades and minimum tensile strength for the as-centrifugal-cast condition at room temperature.
| UNS grade | Main composition by weight | Alloy direction | Minimum tensile strength | General application direction |
|---|---|---|---|---|
| C95200 | Cu ≥86%, Al 8.5–9.5%, Fe 2.5–4% | Aluminum-iron bronze | 448 MPa | Bushings, gears, wear plates and pump parts |
| C95400 | Cu ≥83%, Al 10–11.5%, Fe 3–5%, Ni ≤1.5% | Aluminum-iron bronze | 517 MPa | High-strength bushings, gears, bearings and wear parts |
| C95500 | Cu ≥78%, Al 10–11.5%, Fe 3–5%, Ni 3–5.5% | Nickel aluminum bronze | 621 MPa | Heavily loaded bearings, gears and high-strength components |
| C95800 | Cu ≥79%, Al 8.5–9.5%, Fe 3.5–4.5%, Ni 4–5%, Mn 0.8–1.5% | Nickel aluminum bronze | 586 MPa | Marine hardware, seawater valves, bushings and wear parts |
Mechanical properties change with casting method, heat treatment and section size. The applicable ASTM, EN or customer specification must be confirmed before using published values for design or inspection.
C63000 and C63200 are commonly discussed as wrought nickel aluminum bronze grades. They should be compared using the relevant wrought-product specification rather than inserted directly into a cast-grade property table. The same caution applies when reviewing CuAl10Fe or CuAl10Ni alloy designations from different standards.
Where Is Aluminum Bronze Used?
Typical aluminum bronze application areas include:
| Application area | Typical components |
|---|---|
| Heavy industrial machinery | Bushings, bearing segments, guide parts and wear components |
| Hydroelectric equipment | Large bushings, rings, sealing parts and auxiliary bearing components |
| Pumps and valves | Pump parts, valve bodies, valve seats and guides |
| Marine equipment | Seawater valves, marine hardware, shafts and selected propeller components |
| Transmission systems | Gears, worm wheels, thrust parts and loaded sliding components |
The material should still be checked against the shaft, lubrication method, temperature, water chemistry and expected load. For finished bushing structures and manufacturing options, see our custom aluminum bronze bushings. Large parts used in power-generation equipment are also discussed on our hydroelectric equipment page.
Custom Aluminum Bronze Castings from JEDBUSHING
JEDBUSHING manufactures aluminum bronze bushings, sleeves, rings, thrust parts, bronze wear plates and special-shaped bronze components according to customer drawings or samples.
Depending on the part geometry, size, material grade and quantity, our casting capabilities include centrifugal casting, horizontal continuous casting and vertical metal-mold casting. We can support subsequent CNC machining, material composition checks and CMM dimensional inspection for finished components.
Send the drawing, specified grade, quantity, working condition and inspection requirements. Contact JEDBUSHING for a custom quote.
FAQ
Does aluminum bronze rust or develop a patina?
Aluminum bronze does not form iron rust, but its surface can oxidize or change color over time. Corrosion behavior depends on the grade, environment, water chemistry, temperature and contact with other metals.
Is aluminum bronze magnetic?
Many aluminum bronze alloys have low magnetic permeability, but grades containing iron and nickel may respond differently. If low magnetic permeability is a project requirement, it should be confirmed for the exact grade and condition.
Can aluminum bronze be welded?
Weldability depends on the grade and process. Gas-shielded arc and coated metal arc welding are suitable for several common aluminum bronze grades, while oxyacetylene welding is often not recommended. A qualified welding procedure should be used.
Can aluminum bronze be heat treated?
Some aluminum bronze grades, including selected C95400 and C95500 conditions, can be heat treated to change their mechanical properties. The required treatment and resulting values must follow the applicable material specification.
Is aluminum bronze the same as aluminum brass?
No. Aluminum bronze is primarily a copper-aluminum alloy. Aluminum brass is mainly a copper-zinc alloy with aluminum added. Their compositions, mechanical properties and typical applications are different.