M8 Wing Nut - A4 Stainless Steel See Diagram for dimension key: d = 8 mm Thread Pitch - 1.25 mm D = 13.8 mm e = 30.3 mm h= 14.8 mm m = 5.6 mm A4 grade stainless steel is also known as type 316 S31.This has a greater corrosion resistance than A2 in certain environments, and is often used for Marine applications especially when coming into direct contact with salt water DIN315