CuZn9Pb2 – UNS.C31400 Lead Commercial Bronze Alloys, which is commonly named "Commercial Bronze", and it is a free machining brass with a higher electrical and thermal conductivity than that of standard free machining brass.

C31400 combines the natural corrosion resistance of C22000 with the machinability typical of leaded brasses. Like C22000,it is an alpha brass nominally composed of 89% copper and 9% zinc, but it also contains abt. 2% lead in order to impart free-cutting characteristics.

The relatively low zinc content of C31400 provides excellent corrosion resistance in potable water along with a pleasing golden color that matches C22000 hardware. Alloy C31400 is also suitable for outdoor use due to its resistance to stress corrosion cracking and to corrosion in general, but where the highest strength is not required.