Steel tapping screws are commonly used to join metal to wood, such as drawer slides. These screws tap their own threads and are not intended to be disassembled often. Product Advantages: Fast tapping into metal, plastic and wood, excellent material engagement and thread starting. All Screws under 1" are fully threaded. Screws over 1" are 2/3 threaded to help prevent "jacking" when two materials are fastened together.