M6 Wing Nut - A4 Stainless Steel See Diagram for dimension key: d = 6 mm Thread Pitch - 1 mm D = 12.7 mm e = 27.8 mm h= 13.6 mm m = 5.1 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