Goldscrew Yellow zinc-plated Carbon steel Wood Screw (Dia)3.5mm (L)20mm, Pack of 200. Top quality, waxed single thread, multipurpose screw. Popular with the professional as it features a lower screw-in torque and faster drive speed. Suitable for screwdrivers, combi drills and impact drivers.. This pack of Prodrive drive recess countersunk flat head wood screws are constructed from a durable case and are through hardened. They are 20mm in length and come fully threaded. They have coarse thread and come wax coated for lubrication. They\'re ideal for a range of DIY applications. Woodscrews by Goldscrew.