Whiteside’s 82° Countersink Heads are designed to slip over the drill bit and affix with dual set screws into the flutes. Adjust the drilling length by sliding the head up or down the bit. Use to countersink holes in wood, plastic, or aluminum for flat head screws. Upgrade to the High Speed Steel series for longer life, especially in fiberglass or other abrasive materials. Matching drill bits are offered for your convenience.