These drill bits are designed to work up to 3x faster than standard drill bits thanks to the Bosch Tip Technology. The Bosch patented threaded tip helps the spade bit enter the wood with minimal pressure and in turn, it causes minimal tiring when using them. These bits are suitable for softwood, hardwood, light building materials, and plasterboard. This 8 piece set includes a 12mm,16mm,18mm,20mm,22mm,25mm,28mm and a 32mm spade bit.