Heavy section timer teks are designed to fasten timber, plywood, chipboard and similar materials to metal. The wings are designed to ream a clearance hole in the wood to prevent thread engagement and jacking. The Tek point drills the steel, then the wings break off enabling the threads to engage and the fastener to clamp the wood firmly to the steel. Timber teks must penetrate throught the steel to expose at least two full threads. Light section timber teks must be driven into a minimum of 1.5mm steel thickness to allow wings to break consistently. Heavy Section timber teks are suitable in metal thicknesses 4.0mm – 12.5mm