Cartridge Brass70% copper 30% zinc. This is one of the most widely used of the copper-zinc alloys; it is formable and ductile and possesses excellent cold-working, poor hot working and poor machining properties. Rated excellent for soft-soldering; good for silver alloy brazing or oxyacetylene welding and fair for resistance of carbon arc welding. The alloy develops high tensile strength with cold-working. Temper is obtained by cold rolling.