Abstract: Copper alloys which excel in corrosion resistance, moldability and workability and are particularly suitable for use as materials for valves, cocks, elbows, tees, etc. or cast parts associated therewith. One copper alloy comprising by weight 27.0 - 32.0% zinc, 0.8 - 4.0% lead, 0.2 - 0.8% silicon, 0.1 - 2.0% manganese, 0.01 - 0.1% arsenic and 0.03 - 0.4% aluminum the rest being composed of copper; and the other copper alloy comprising by weight 27.0 - 32.0% zinc, 0.8 - 4.0% lead, 0.2 - 0.8% silicon, 0.1 - 2.0 manganese, 0.01 - 0.1% arsenic, 0.03 - 0.4% aluminum and 0.01 - 1.0% tin the rest being composed of copper.