FASTENING COPPER ALLOY

摘要

A copper alloy for fastening wherein the alloy has a structure of a mixture of ±-phase and a ²-phase; and wherein the alloy has a composition represented by the general formula: Cu bal .Zn a Mn b , where bal., a, and b are expressed in % by mass, bal. represents the balance, 34 ‰¤ a ‰¤ 40.5, 0.1 ‰¤ b ‰¤ 6, and inevitable impurities may be contained; and the composition satisfying the following equations (1) and (2): b ‰¤ (-8a + 300)/7, where 34 ‰¤ a < 37.5 -(1), b ‰¤ (-5.5a + 225.25)/5, where 35.5 ‰¤ a ‰¤ 40.5 - (2) .