Fig. 165.
Sharp peg-calk
(cog):
a, the tap;
b, the head.
Fig. 166.
Blunt
peg-calk:
a, the tap;
b, the head.
Fig. 167.
Lower
part of
the reamer.
Although the calk-holes may be punched in a hot shoe, yet boring and reaming them is much better, because by this method a more perfect fit can be secured. For this purpose we require a drill (a spiral drill is the best) whose diameter is exactly the same as that of the small end of the calk-tap ([Figs. 165, c], and [166, c]). After the shoe has been fitted to the hoof, the provisional holes are drilled and afterwards reamed out from the ground-surface of the shoe with the reamer shown in [Fig. 167]. Since the tap of the reamer corresponds exactly in size to the tap of the calk, it is evident that the latter must exactly fit and be tight. The wire edge that is raised around the hole is removed with a file, and the edge then smoothed by introducing the reamer a second time. The calks are made of rolled round steel, which has the thickness of the tap-end of the calk. For this purpose we require a calk-mould or matrix, in which one or more holes have been finished with a reamer. A piece of rod steel is heated at the end for a distance nearly twice the length of the calk, is swaged, thrust into the matrix, then broken off, and back-set. This will give a blunt peg-calk. If a sharp calk is desired, the upper part of the head of the calk is sharpened in the ordinary manner, although this is accomplished most easily by using a pair of tongs with short jaws that are hollowed upon the inside for seizing the tap of the calk.