UNC Hexagon full nut 1/2 inch -13 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: 1/2" x 13 TPI 21 mm Across the flats 19 mm Point to Point 10 mm thickness
