The Evolution A4 Stainless Steel Hex Head Gash Point Multi-fix Masonry Screw is designed for fixing timber battens, trunking, track and general components into concrete, masonry and timber. Thread and Head are made with AISI A316 (A4) and the drilling point is made with SAE C1018 / C1022 (Hardened), with a passivated electroplated zinc coating.