Cuts lengthwise dovetail required to install special handgun front sights from Jim Clark, Ed Brown, Bob Marvel and others. Slightly undersized to allow for precise final fitting and to compensate for any machine wear. CAUTION: For use in milling machine only. High speed steel. .300' (7.3mm) diameter cut, 3⁄8' (9.5mm) diameter shank. 60° or 65° shoulder. DO NOT EXCEED 700 rpm, HIGHER SPEED WILL BREAK TEETH.