【Sharp and Sturdy】Our M2 HSS countersink bit features a spiral chip flute for rapid cutting. The sharp alloy cutting edges create smooth countersink and counterbore holes. 【Countersink Drill Bit for Wood】The set includes 5 high-speed steel (HSS) M2 tapered bits in sizes 1/8", 9/64", 5/32" drills+ 3/8” 82° counter-bore and 11/64" ,3/16" drills+ 1/2" 82° counterbore and a 1/4” hex shank.
eBay