Countersunk Self Drilling Wing Tip Screw Heavy Steel 5.5 x 100mm Box 100

Specifically designed to attach timber (64 – 78mm thick) to heavy section steel (Max. 12mm). Metric thread with wings designed to ream out the timber, so the screw can achieve Max. R.P.M. without burning out. When the wings hit the metal they will break off to permit the thread to self-tap into the metal. NOTE: Partially threaded. Can also be used to fix other materials to heavy section steel, please note that the wings will only work in timber and some PVC frames. Aluminium and other frame materials may require pre-drilling prior to enable the self drilling screw to drill through the metal section without threading into the frame.