These Bremick Wing Tip Self Screws are great when fixing timber to steel, as the wings are necessary when fastening these thick materials. The wings ensure that material jacking is reduced specifically due to the clearance holes created by the wings. The tips are designed to eliminate the need for pre-drilling as well. Its countersunk head allows for a perfectly tapered fastening job so you wouldn't have to worry about getting scraped by protruding screw heads. With its C3 galvanisation, it has excellent corrosion resistance making it great for internal and external applications. - Great for fixing timber to metal - Countersunk head