A lead-free free-
cutting copper alloy having 69 to 79 percent, by weight, of
copper; greater than 3 percent, by weight, of
silicon; and a remaining percent, by weight, of
zinc. The
alloy preferable has greater than 3.0 percent and less than or equal to 4.0 percent, by weight, of
silicon; and at least one element selected from among 0.02 to 0.4 percent, by weight, of
bismuth, 0.02 to 0.4 percent, by weight, of
tellurium, and 0.02 to 0.4 percent, by weight, of
selenium. The
alloy also preferable has at least one element selected from among 0.3 to 3.5 percent, by weight, of
tin, 1.0 to 3.5 percent, by weight, of aluminum, and 0.02 to 0.25 percent, by weight, of
phosphorus. In further embodiments, the alloy has at least one element selected from among 0.02 to 0.15 percent, by weight, of
antimony, and 0.02 to 0.15 percent, by weight, of
arsenic.