Aluminium brass—also spelled aluminum brass—is a copper-zinc alloy containing a controlled amount of aluminium. Unlike aluminium bronze, zinc remains one of its principal alloying elements.
It is not one single material grade. C68700, for example, is a wrought arsenical aluminium brass commonly supplied as condenser and heat exchanger tubing. Other complex aluminium brasses contain more aluminium, iron or manganese and may be selected for higher-strength mechanical parts.
This distinction matters when specifying bushings, wear plates or bearing components. At JEDBUSHING, we do not treat “aluminium brass” as a complete material specification. The alloy grade, standard, product form and working conditions must be confirmed before manufacturing.
What Is Aluminium Brass Made Of?
The base system is copper-zinc-aluminium, but the function of each element is different:
- Copper forms the main alloy matrix and contributes corrosion resistance and thermal conductivity.
- Zinc affects strength, hardness, phase structure, formability and cost.
- Aluminium improves strength and helps form a protective surface film in suitable environments.
- Arsenic is added to certain tube grades, such as C68700, to improve resistance to dezincification.
- Iron and manganese may be added to complex high-strength grades to strengthen the matrix and improve wear performance.
- Nickel or other elements may be present in specific proprietary or national-standard alloys.
A chemical composition taken from one grade should never be presented as the composition of every aluminium brass. More aluminium or manganese does not automatically mean that an alloy is better. These additions also change ductility, machinability, casting behaviour and welding performance.
Common Aluminium Brass Grades and Naming Differences
International and Chinese standards do not always classify or name these alloys in exactly the same way.
| Grade | Composition or classification | Important distinction |
|---|---|---|
| C68700 | Cu 76–79%, Al 1.8–2.5%, As 0.02–0.06%, Zn balance | Wrought arsenical aluminium brass used mainly for condenser and heat exchanger tubes |
| HAl77-2 | Nominally about 77% Cu and 2% Al, with Zn as the main balance | Chinese aluminium brass grade with chemistry close to C68700, but the two should not be assumed interchangeable without checking the standard |
| HAl66-6-3-2 | Nominal designation indicates approximately 66% Cu, 6% Al, 3% Fe and 2% Mn | Complex high-strength aluminium brass used for specified mechanical applications |
| C86300 | Cu 60–66%, Zn 22–28%, Al 5–7.5%, Fe 2–4%, Mn 2.5–5% | Classified in the UNS system as cast manganese bronze or high-strength yellow brass—not as C68700-type aluminium brass |
| C86400 | Cu 56–62%, Zn 34–42%, Al 0.5–1.5% with Fe, Mn and lead | Also classified as a cast manganese bronze/high-strength yellow brass |
The naming difference is especially important in the bushing industry. C86300 and C86400 contain aluminium and are frequently shown in searches for “aluminum brass bushings,” but the Copper Development Association classifies C86300 and C86400 as cast high-strength yellow brasses or manganese bronzes.
Therefore, a purchase order should state the complete grade and applicable standard—not only “aluminium brass.”
Key Properties and Practical Limitations
The properties of aluminium brass vary considerably with grade, product form and temper.
For reference, the Copper Development Association lists the following typical room-temperature data for C68700 tube:
- Density: 8.33 g/cm³
- Typical tensile strength: 414 MPa
- Typical yield strength: 186 MPa
- Typical elongation: 55%
- Thermal conductivity: approximately 100 W/m·K
- Electrical conductivity: 23% IACS
These figures describe a specific wrought tube condition. They must not be used as the design values for a cast bushing or wear plate.
In practical service, aluminium brass may offer:
- good corrosion and erosion resistance in appropriate flowing-water conditions;
- higher strength than ordinary cartridge brass;
- useful thermal conductivity;
- good cold-working capability in certain wrought grades;
- higher strength and wear resistance in selected complex grades.
Its limitations must also be considered. Protective-film performance can be affected by stagnant water, deposits, contamination and unsuitable flow conditions. As a brass, it may remain vulnerable to stress-corrosion cracking in certain ammonia-containing environments. High-aluminium or high-strength grades may also be less ductile and more difficult to machine or weld.
Material selection should therefore be based on the actual service environment, not on corrosion resistance alone.
What Is Aluminium Brass Used For?
Its applications depend on the grade and product form.
| Application | Common material family | Selection reason |
|---|---|---|
| Condenser and heat exchanger tubes | C68700 or HAl77-2 | Corrosion resistance, erosion resistance and thermal conductivity |
| Distiller tubes and ferrules | Wrought arsenical aluminium brass | Resistance to fresh water or saltwater service |
| Pump and valve parts | Drawing-specified complex aluminium brass or high-strength brass | Strength, corrosion resistance and machinability |
| Bushings, wear rings and slow-speed bearings | Selected cast high-strength brass grades | Load capacity, wear resistance and dimensional stability |
| Thrust washers and special machined parts | Grade selected by drawing and working condition | Custom geometry, fitting and wear requirements |
C68700 should not automatically be selected for a bushing simply because it performs well as a heat exchanger tube. A tube alloy and a heavy-load bearing alloy may require very different strength, hardness and manufacturing routes.
Aluminium Brass vs Aluminium Bronze
The similar names often cause incorrect quotations and material substitutions.
| Comparison | Aluminium brass | Aluminium bronze |
|---|---|---|
| Base alloy system | Copper-zinc-aluminium | Copper-aluminium |
| Zinc content | A major alloying element | Normally absent or only residual |
| Typical grades | C68700, HAl77-2, complex HAl grades | C95400, C95500, C95800 |
| Common product forms | Tubes, wrought parts and some high-strength mechanical alloys | Castings, forgings, bushings and heavy-duty wear parts |
| Typical selection focus | Water-side corrosion, thermal service or grade-specific mechanical performance | High strength, heavy load, impact and marine service |
| Direct substitution | Not recommended without engineering review | Not recommended without engineering review |
For heavy-load bushings or impact-loaded components, aluminum bronze bushings may be considered. However, aluminium bronze is not automatically superior. The correct choice depends on the required grade, load, sliding speed, lubrication, corrosion environment and mating material.
Can Aluminium Brass Be Used for Bushings and Wear Parts?
Yes, but only selected grades and working conditions are suitable.
Before manufacturing custom aluminum brass bushings, the following should be checked:
- projected bearing pressure;
- shaft speed and calculated PV value;
- continuous, intermittent or oscillating motion;
- lubrication method and lubricant supply;
- shaft hardness and surface finish;
- required running clearance;
- edge loading or possible misalignment;
- water, chemicals, dust or abrasive contamination;
- operating temperature;
- required material standard and casting form.
Material strength alone does not determine service life. Incorrect clearance, insufficient lubrication, rough mating surfaces, poorly positioned oil grooves and shaft misalignment can cause premature wear even when the specified alloy is correct.
The same principle applies to bronze wear plates. Aluminium brass may be used when required by the drawing, but tin bronze, aluminium bronze or graphite-plugged bronze may be more suitable for other sliding conditions.
For high-speed hydrodynamic journal bearings, a babbitt-lined bearing can represent a completely different bearing solution. It should not be replaced with solid aluminium brass simply because both parts are described as bearing shells.
From Material Grade to Finished Parts at JEDBUSHING
JEDBUSHING manufactures custom copper-alloy wear components, including sleeve and flanged bushings, wear plates, thrust washers, bearing shells and special-shaped bronze parts.
Our manufacturing support includes:
- bronze bushing manufacturing experience since 1998;
- approximately 1,500 tons per year of casting and machining capacity;
- drawing, sample and material-standard review;
- selection of cast or wrought starting material;
- CNC machining of IDs, ODs, flanges, grooves, holes and slots;
- temperature-controlled machining and inspection support;
- dimensional inspection using two large CMMs;
- material certificates and inspection reports when required.
A drawing should identify the grade, standard, dimensions, tolerances and inspection requirements. If the original drawing is unavailable, an old sample, photographs and operating information can be reviewed first.
See the information recommended for a custom bronze bushing quote, or send your drawing to JEDBUSHING for material and manufacturing review.
FAQ
Does every aluminium brass grade contain arsenic?
No. Arsenic is included in certain grades such as C68700 to improve resistance to dezincification. Complex high-strength aluminium brasses may use iron, manganese or other alloying elements instead.
Is aluminium brass always lead-free?
No. Lead limits depend on the specific grade. C68700 has a very low permitted lead content, while some cast high-strength brasses intentionally contain more lead to improve machinability. Regulatory requirements must be checked separately.
Can an aluminium brass grade be identified by its colour?
No. Aluminium brass, manganese bronze, aluminium bronze and other copper alloys can have similar yellow or golden surfaces. Reliable identification requires a material certificate, chemical composition analysis or verified original specification.