Disc Spring, Curved, High Carbon Steel, Min Inside Dia 0.331 In, Max Outside Dia 0.490 In, Thickness 0.008 In, Overall Height 0.077 In, For Hole Size 1/2 In, For Rod Size 5/16 In, Load 1.7 Lbs, Deflection @ Load 0.028 In, Meets/Exceeds ASTM-A684, Package 10