HeadLok is a heavy duty wood screw that does it all with an internal drive and flat head. HeadLok offers higher design shear than 3/8 in. lag screws and no predrilling is needed. HeadLok zips right in and is ideal for many wood-to-wood applications including decks, fences, SIPs, kitchen cabinets and more. The patented SpiderDrive eliminates cam-out and improves installation speed.