M8 A4 SS HALF NUT (DIN 439) A4 grade stainless steel has a greater corrosion resistance than A2 in certain environments. It is often used for Marine applications especially when coming into direct contact with salt water Manufactured to the Din 934 standard Thread Pitch - 1.25 mm M8 - Minimum thickness: 3.7 mm Across flats:13 mm DIN439