Gunmetal Casting Alloy – B61

B61 ASTM Casting Alloy

B61 is a leaded tin bronze gunmetal alloy and has high strength. Gunmetal alloys are useful for many applications because of their combination of high strength in tension and compression, hardness, ductility and high resistance to impact. This alloy is also known as ‘red brass’.

This material is used in a variety of applications. Typical uses for this alloy are: Valves, fittings, and pressure containing parts.

B61 ASTM Chemical Composition


Copper 86.0-90.0

Zinc 3.0-5.0

Lead 1.0-2.0

Tin 5.5-6.5

Silicon 0.005 max

Iron 0.25 max

Phosphorous 0.05 max

Antimony 0.25 max

Sulhur 0.05 max

Aluminium 0.005 max