M10 DIN 986 Hexagon Domed Cap Nut with Nylon Insert - A2 Stainless Steel Works in a similar way to Nyloc nuts. The non-metalic (nylon) insert helps to “lock” the nut in place. Sometimes called a prevailing torque type nut Measurements in mm: Thread Size: m = 8.04 mm h = 18.1 mm s = 16 mm e = 18.9 mm Thread pitch : 1.5 mm A2 (T304) Grade Stainless Steel