To facilitate the forging of keys of various shapes and dimensions, a number of blocks are cast having recesses and grooves of different shapes corresponding to the shapes of the keys required. For round keys, half-round taper recesses are formed; for square and other kinds of rectangular keys, the recesses are about the same depth as the thickness or width of the intended keys, some of the gaps being used for shaping the keys while their small sides are upwards, and other recesses being used for shaping the keys while their broad sides are upwards. The bottoms of the gaps may be either flat or curved, according to the required shapes of the key-sides.

Keys having heads are shaped by hammering them into gaps that are shaped to receive the heads in addition to the stems of the keys. The gaps for the heads may be open at the front end of the shaping-block near the workman, or the recess for the head may be made nearer to the middle of the block-face; the recess will then be surrounded with metal, except at the place for containing the key-stem. This situation for the heading recess is necessary for shaping great numbers of headed keys, that they may be firmly retained in their respective recesses instead of being pushed out with the hammering.

The tools that are required while hammering the metal into the shapers are half-round top tools and flatters, or, in some cases, the hammer only. The half-round top tools are used for round keys and the small sides of taper flat keys, also one of the small sides of a gib. Flatters are necessary for all sorts of rectangular keys; and when considerable numbers are wanted of similar width and thickness, the required dimensions are obtained by hammering each key into two gaps, one gap being just the width of the required keys, and the other gap being just the thickness. When two such gaps are provided, they are termed gauge-gaps; and while the key is in either of these openings, it is flattened with a flatter until the flatter strikes the face of the block at the same time that it strikes the key, at which time the work is of the required dimensions, measuring with callipers not being necessary in such cases.

Many classes of keys can be shaped and reduced to the finished dimensions at only one heating and hammering; for such keys only one gauge-gap is requisite for each size of keys.

The material used for such shapers should be cast Bessemer steel, the proper care being exercised to slightly taper the gaps that the work may be easily separated from the shapers. A key-shaper is shown by Fig. 213.