A2 stainless steel Spax wood screws, 4.5 x 35mm, with a flat countersunk head and a TX T20 drive, in a plain stainless finish. Supplied as 200 pieces in a box. Stainless steel is chosen where resistance to corrosion is wanted. The TX recess is designed to give a firm fit with a T20 driver bit, and the countersunk head sits flush with or just below the surface of the timber. Check the screw size against your material before you start, and drill a pilot hole where recommended to reduce the risk of splitting the wood.