UNC Hexagon full nut 5/16 inch -18 A4 Stainless Steel 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 Dimensions: 5 /16" x 18 TPI 14 mm Across the flats 12 mm Point to Point 6 mm thickness
