What is CA104 Aluminium Bronze?

What is CA104 aluminium bronze?

Aluminium bronze CA104 is an alloy that contains aluminium, iron, nickel, and copper. CA104 is the wrought form of 10/5/5 aluminium bronze and is comparable to BS1400 AB2 if a cast equivalent is sought. Key attributes of CA104 grade aluminium bronze are that it has a high mechanical strength, excellent erosion and corrosion resistance, high resistance to abrasion and wear, and retains its mechanical properties throughout the cryogenic temperature range (-150°C and below)

Chemical composition by weight of CA104


















Total impurities












0.50 max


Mechanical properties of CA104

Ultimate Tensile Strength

650 - 700 Min MPa

0.2% Proof Stress

320 - 400 Min MPa

Elongation A

10-15 %

Hardness Brinell

170 - 210 HB


Physical properties of CA104

Melting point




Thermal conductivity

37.7 W/m.K

Modulus of elasticity

115 GPa



What is CA104 commonly used for?

Aluminium bronze has excellent corrosion resistance and performs especially well in hostile marine and high chloride environments. The addition of tin in this grade of aluminium bronze increases its resistance to seawater, making it a great option for manufacturing marine equipment and parts submerged in harsh saltwater environments. It is also resistant to other strong chemicals including alkalis and acids, making it a popular choice for use in chemical industries such as petrochemical, defence, offshore, and aerospace sectors.

CA104 grade is non sparking, non-magnetic, has low electrical conductivity, and has excellent tolerance to shock loading, making it a strong choice for the manufacture of components such as valve stems and seats, marine hardware, thrust washers, worm gears, high strength fasteners, bushes and bearings, pump and engine components, and other high temperature applications.


Can CA104 be machined or welded?


Aluminium bronze CA104 has fair to good machinability. While machining, care does need to be taken to avoid overheating as this can lessen the metal’s wear resistance and strength. If the workpiece is ‘forced’ during machining it may chip or tear, therefore, for best results use very sharp tools using appropriate speed and feed settings. It is also recommended to use an appropriate coolant to reduce the risk of work hardening.


CA104 overall has varying weldability properties depending on the method being used..

Gas shielded arc welding (GMAW, MIG, MAG,GTAW, TIG) is rated as excellent.

Spot welding, shielded metal arc welding (SMAW, MMA,MMAW), and butt welding are rated as good.

Soldering, oxy-acetylene welding, and seam welding is rated as fair.

Please be aware that the welding process can change the bronze’s properties, including its strength, wear resistance, and corrosion resistance. To reduce these effects, all welding should be done with a suitable filler material and using the correct techniques.

How does CA104 compare to other bronze grades?

We supply bronze in grades SAE660, PB102, and PB1 in addition to our CA104 aluminium bronze range. The main difference is their chemical composition. The addition of certain elements alters the mechanical and physical properties of alloys to create a range of products that offer alternatives depending on the requirements of your project.

Bronze is made primarily from copper; the addition of other metals increases the hardness and alters the properties of the metal than it is if it remained unalloyed.

SAE660 has tin, lead, and zinc to improve its dry running and sliding properties and will not dezincify. Excellent anti- friction properties make this grade suitable for valves, bearings, and bushings.

PB102 has the addition of tin which enhances its spring quality and provides a high resistance to corrosion like CA104; it is widely used in the manufacture of  general engineering components.

PB1, also known as ‘phosphor bronze ’, has phosphor added to enhance its stiffness and wear resistance; its high corrosion resistance to brine and excellent resistance to wear makes it a strong option for applications such as hydraulics and high workload gears.

Cost is also a factor to consider when selecting the correct material for your project. Aluminium bronze will be the costlier option due to its improved strength and performance in higher specification applications. However, it is always best to consider the required outcome and performance when choosing materials to ensure success, safety,  and reliability of components.

We supply CA104 aluminium bronze as round bar in a range of diameters from ½” to 3”.