About this item 15 Pcs Countersink Drill Bit Set The set includes 15 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° counter bore and 1/4” Hex Shank for a secure grip, universal compatibility. Quick release Hex shank. No Wobble. Depth Adjustable Drill bits can be replaced Try a few holes to make sure it’s your desired depth and hole diameter. Both pilot drill and counterbore depth are adjustable by adjusting the depth stop and drill bit with the wrench included, to achieve accurate drilling.The added plastics Free Spinning collar can reduce surface marring effectively. Sharp And Sturdy The M2 HSS pilot drill bits with spiral chip flute,cutting edges create smooth countersink and counterbore holes ensuring smooth, burr-free cutting performance; ideal for screws fitting 82-degree imperial (U.S.) standards. Widely Used Working with MDF, Plywood, Non-Ferrous, Chipboard, ,natural woods, man-made boards,decking,drywall,various plastic boards decking materials, and high-density polyethylene (HDPE).Wood drill bit for best results and smooth edges operate the countersink at slow speeds, approximately 200 RPM. Portable And Convenient The carrying case contains 5 countersink drill bits, 10 high-speed steel (HSS) M2 tapered bits, an additional plastic free spinning collar, an Allen wrench, so it’s straight forward to carry everywhere. The hanging hole of the wood drill bit set design allows you to hang it freely., only 12.35ounces/350g weight so it’s very easy to carry everywhere.