Beta Pin / R Pin T304 (A2) Stainless Steel 2.5 mm x 46 mm Also known as a Clevis Pin, R-key, bridge pin, hairpin cotter pin, hairpin cotter, bridge pin, hitch pin or spring cotter pin, is a fastener made of a springy material, commonly in the shape of the letter 'R' or the greek letter 'Beta'. T304 (A2) grade Stainless Steel Dimensions: D (mm) = 2.5 D1 (mm) = 11 L (mm) = 54