M8 Countersunk Head Blind Rivet Nut - T316 (A4) Stainless Steel The countersunk head style provides a stronger head and will install flush in a countersunk hole Grip Range: 1.5-4.0 mm Hole Diameter +0.1 / -0.0: 11 mm Body Diameter: 10.9 mm Head Diameter: 13.5 mm Head Thickness: 1.5 mm Overall Length: 18 mm Material Finish T316 Stainless Steel is suitable for anywhere you would use T304 BUT has the added advantage of being suitable for marine solutions. The molybdenum increases the corrosion resistance to withstand attack from many industrial chemicals and solvents and of course chlorides