M5 Wing Nut - A4 Stainless Steel See Diagram for dimension key: d = 5 mm Thread Pitch - 0.8 mm D = 10.3 mm e = 22.5 mm h= 11 mm m = 11 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