Drill Arbors

A spear-shaped tool or flat drill having cutting edges on the flattened end, a male center at the other end and a pulley, or ferrule, on its elongated shank. It is rotated for drilling by the use of a drill bow, which produces reciprocating motion. In use the drill arbor is supported at the cutting end by the drill point and at the other in a center hole of a breast plate, or in a hole in the end of a vice jaw or vice block. This type of drill, depending on the exact shape of the cutting edges, when used with plenty of oil will penetrate hard brass or even tempered steel. The name is also given to pintongs which are intended to hold a drill and be rotated in a large chuck or collet.