When great packing numbers of bolts having cylindrical heads are wanted, it is advisable to use an implement which will reduce the bolt-head to its proper diameter, also reduce the bolt-stem to its diameter, and make the bolt-head concentric with the bolt-stem, the three objects being effected at only one hammering. The lower block of such an apparatus is shown by Fig. 215. The upper shaper consists of a top tool having a recess, which is of the same shape as that in the bottom tool. After a bolt is drawn down and roughly shaped, it is put between the two tools and adjusted to the desired shape and dimensions at one or two heats.

Shapers of this sort will not adjust a bolt-head to any particular length ; it is therefore necessary to make the recesses for the heads longer than the length of the longest bolt-head to be put within. The easiest method of making such shapers is by casting, the recesses being formed at that time.

Another plan consists in casting or forging the top and bottom blocks separately and without any recess. The next step is to carefully flatten the two faces that are to come together ; after this the two tools are firmly bolted together in their intended relative positions during use. While thus fixed, the bolt-holes and head-recesses are bored with suitable apparatus.