Description: Single edge chamfering device 90 ° Suitable for hardness lower material, such as wood For use with Cordless drills , regular drills, drill presses, or low rpm rotary tools. Great for making countersink holes for counter sunken screw heads as well as counterbored holes for plugs. Shank: round handle Material: HSS Quantiy: 1 Set 6Pieces (6.3, 8.3, 10.4, 12.4, 16.5, 20.5mm) Package Includes: 6Pieces Countersink bits