Leaded Brass

Free-machining brass contains about 58% copper and 39% zinc. Lead is added to improve machinability, in content of 1-3%wt. The microstructure is constituted by two phases, α and β. Duplex brass is easier to be hot worked by extrusion or stamping and machine.

Generally, an increase of  Zn content produces stronger alloys with a moderate decrease in corrosion resistance and cold ductility. Other alloys required to be free-machining , yet retaining sufficient ductility for riveting or other cold work, contain less lead and more copper.

Halcor can produce leaded brass rods, flat bars, sections and wires.

Properties

Lead isn’t soluble in a copper matrix and for that reason lead is dispersed homogenously in the form of fine globules in the microstructure. Lead acts as a lubricant decreasing the friction coefficient between the tool and the material, creating discontinuities that promote the chip fragmentation, reducing the cutting force and the tool wear rate.

Additions of other elements such as manganese, tin, aluminum, iron, silicon and arsenic may be used to improve strength and corrosion resistance. Leaded brass is used for its excellent machinability, good strength and atmospheric corrosion resistance.

Applications

Leaded  brass is used for architectural hardware, general purpose screw machine parts, screws, valves, fittings, bearings and specialty fasteners.