Hexagonal bolt-heads after being lathe-turned, require the six planes to be produced, either by means of a small shaper, or with a planing-machine, the particular machine selected being suited to the dimensions of the heads to be shaped. Heads that are only about two or three inches in diameter, are shaped on a table of a small shaping-machine; several may be fixed at one time, and the bolts are so situated that their lengths are parallel to each other, and parallel to the to-and-fro motion of the cutting tool, the bolt-heads being in line with each other and near together. While thus situated one plane of each head can be produced at one planing by only one fixing; and for this purpose the stems of the bolts are supported in the notches of vee-blocks, and packed up to a proper height above the table. This packing-up is not necessary if all the bolt-heads to be shaped are of similar dimensions and belong to bolts of similar diameters; but by means of packing-pieces of various thicknesses, a number of heads belonging to bolts of different diameters may be placed at any desired height; in order that all the planes that are to be produced at one operation shall be at the same height from the table. If the bolts are only a few inches in length, one vee-block is sufficient for each bolt if it has a broad vee-notch; but bolts of one or two feet in length require two blocks for each bolt, one block being situated near the bolt-head and the other one near the junction of the stem with the screw. When only one bolt is to be planed by this means, its length is quickty placed parallel with the table as required, by a pair of vee-blocks being put beneath ; but when several bolts are being fixed, and packing-pieces are used, it is necessary to place a scriber-block upon the table with the scriber-point at the centre recesses of the bolt-ends, in order to ascertain what thicknesses of packing are required to place both ends of the bolts at the proper heights.

The planing of large six-sided heads that may be nine or ten inches across, is done on planing-machines, because a large table is required on which to place several bolts together at one time, that all, or nearly all, of the bolts' lengths may rest on the table. The placing of the stems on vee-blocks, the packing-up, and the adjustment of the bolts' axes to parallelism with the table, is similar to that mentioned for smaller bolts on shaping-machines. "While bolts are on planing-tables their lengths may be either parallel with the direction of the table's motion, or at right-angles to it, the situation depending on the lengths of the bolts and the size of the machine employed.

All bolts, small and large, whether fixed on shaping-machines or on planing-machines, if fixed, as just described, in vee-blocks, may have all the six planes of each lot of bolts produced while the bolts are in the same situation as when first fixed, it being only necessary to loosen the hold-fast bolts after one set of planes are produced, and rotate the bolts a short distance without removing them from the vee-notches, in order to again fasten them by tightening the bolts, to prepare for another planing. In consequence of this gradual rotation being effected it will be seen that sufficient room between the bolt-heads must be allowed, that they may be freely shifted.