7pcs HSS 5 Flute Countersink Drill Bit Set 3mm-10mm
These countersink bits are sturdy and durable and perform well. These countersink drill bits are HSS material and are made to last and perform. A countersink is a conical hole cut into a manufactured object, or the cutter used to cut such a hole. A common use is to allow the head of a countersunk bolt or screw, when placed in the hole, to sit flush with or below the surface of the surrounding material (by comparison, a counterbore makes a flat-bottomed hole that might be used with a socket-head capscrew). A countersink may also be used to remove the burr left from a drilling or tapping operation thereby improving the finish of the product and removing any hazardous sharp edges.