Distinctive gold bits, bearings and pivot pin signify the longest lasting, fastest cutting, easiest adjusting solution for cutting holes in sheet metal. Our hole cutters quickly install into the chuck of any corded or cordless drill as small as 1/4 In. (6. 4 mm). Lightweight aluminum frames make these accessories extremely portable for a variety of hole cutting applications in sheet metal including 20-gauge (1. 02 mm) galvanized steel. 2 per pack.