UNC Hexagon full nut 1/4 inch -20 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 Material : T316 Stainless Steel (A4) Product Type : Nuts – Hex – UNC Thread Size : 1/4 UNCDimensions: 1/4″ x 20 TPI12 mm Across the flats11 mm Point to Point5 mm thickness