Wing Tip Self Drilling Screw - Light 5.5mm x 130mm 4mm but often there primary use

but often there primary use is for joining window frames and sills together to create bay windows

which are the mechanical hinges that allow windows to open and stay in position without the need for additional mechanisms

Securing friction stays to the frame: They fasten the friction stay hinges to the window frame or sash

Extensively used for extending the length of threaded bar

Wing Tip Self Drilling Screw - Light 5.5mm x 130mm 4mm but often there primary useSelf Drilling Wing Tip Screw For use with Light Section Steel 5. 5mm x 130mm These wing tip self drilling screws are specifically designed to attach wood to light section steel, with a maximum recommended steel depth of 5mm. Designed with a coarse self tapping thread, the wings ream out the timber whilst drilling to ensure a clean and secure fixing, achieving max RPM without burning out. Once the specially designed wings hit the metal they will break