10X LONGER LIFE than normal metal hole saws Our tungsten carbide tipped hole saws are a superior alternative to conventional bi-metal hole saws. They cut faster, cleaner and last longer. Tungsten knives cut sheet steel, iron, aluminum, copper, cast iron and most importantly, stainless steel and other tough alloys. < p> Spring-loaded pilot drill ejects cut ingot, saving time. The cutter body then cuts a clean, burr-free hole faster than conventional twist drills or hole saws. With normal maintenance, tool life is significantly longer than other hole cutting tools. Inexpensive resharpening will allow for repeated use