Disc Spring Belleville 302 Stainless Steel Min Inside Dia 0.505 In Max Outside Dia 1.000 In Thickness 0.043 In Overall Height 0.071 In Load 250 Lbs Deflection @ Load 0.014 In Flat Load 431 Lbs Meets/Exceeds ASI 302 and Government AMS Type 302 Package 12