Spax Wirox Washer Head Screw Zinc Nickel 6 x 140mm is suitable for using on timber to timber applications such as battens and square timbers. The universal construction screws can be used both internally and externally as they have a Wirox coating to provide anti-corrosion protection. The washer head design provides the screw with an increased strength and tighter grip once the screw has been inserted. No pre-drilling is required for these screws.