The punch shown by Fig. 337 is a sort of drift having a short bearing with a small number of cutting edges, or with only one cutting part, which is the outer extremity of the thickest part of the tool. The thinner portion of the tool is its handle, and a part of this extends into the hole which is being drifted, but does not touch anything, consequently the friction while driving the tool is confined to the cutting edges and a short portion of the thick part, and this allows the tool to be driven through a piece of work quicker and easier than a drift having a longer bearing and a greater number of teeth, resembling Fig. 333 or 334; but a drift having only a short bearing is not so advantageous for making long straight holes ; consequently, a drift having one cutting edge and a short bearing is suitable for finishing short holes, and a drift with a long bearing is proper for finishing long holes. With this object, a drift with a short bearing may be first hammered through the work in progress, which is afterwards finished with a drift having a longer bearing.

The punch shown by Fig. 338 is a cutting tool whose extremity is bounded by a circle, and is'made to form round holes into plates of various metals by being held in one hand while the other hand hammers the punch through the plate. To make holes in this manner, the punch is used with a die or bolster, and this a thick steel ring or block having a round hole which is rather larger than the cutting end of the punch, this hole being intended to receive the cutting end of the punch after it is hammered through the plate. When punching is to be performed, the plate is first marked with a dotting punch, compasses, or some other means, to indicate the places of the intended holes, and the punching is begun without the bolster, by putting the plate across a larger hole, and hammering the punch a short distance into the plate ; by this means a bump is formed upon the under side of the plate, and this projection is next slid along, or the bolster is moved along, until the bump slips into the bolster-hole; after which, the punch end is hammered through the plate, and the piece which is cut from the work falls into the bolster-hole. Circular punches are useful also for smoothing bottoms of recesses in various pieces of work. Fig. 339 represents a punch having a half round cutting end instead of a round one; Fig. 340 indicates a punch with a rectangular end, and both these tools are used with bolsters in a manner resembling that described for round punches.