7-Pc. Split Collar Set

Split-ring stop collars clamp around drill bits and hold securely in place. When tightened, they clamp over the complete diameter of the drill bit shaft without marring. The set includes collars for 1/8", 3/16", 1/4", 5/16", 3/8", 7/16" and 1/2" size bits. A 3mm (1/9") hex key for adjustments is also included with the set. Select the proper collar diameter, slide it onto the drill bit, and tighten the single 3mm hex screw. The split ring design tightens fully around the drill bit securing it in place. No damage to the drill's side edges or flutes will occur! Stop Collars allow you to set precise cutting depths on any countersink or drill bit with a corresponding diameter.