Patent ID: 7628873

Claim:
A beryllium copper alloy, comprising: a thickness “t” in a range from 0.05 mm to 0.5 mm; an alloy composition consisting by weight (or mass %) of Cu 100−(a+b) Ni a Be b , wherein 1.0≦a≦2.0, 0.15≦b≦0.35, and 5.5≦a/b≦6.5; a 0.2% proof stress equal to or above 650 MPa; an electric conductivity equal to or above 70% IACS; and a bending formability defined by a ratio of R/t=0, wherein “R” is a maximum bend radius before cracking at a bent portion when the beryllium copper alloy is bent into a V shape at a right angle.