Wheel prickers (Figs. 33 and 34) are used in sizes from seven or eight to sixteen teeth to the inch. They are round pieces of steel, having serrated edges and a hole in the centre, and are provided with a handle in which they are adjusted with a pin and nut. A change of stitch, say from fine to coarse, necessitates a change of wheel. The wheel is run along the stitching line, and in the holes made by the pricks the stitches are run.
The screw-race (Fig. 35) is a tool for grooving lines in any part where it is desired to sink the stitches below the surface. It is easily adjustable.
Fig. 35.
Fig. 36.
Fig. 37.
Fig. 35.—Screw-race. Fig. 36.—Single Crease. Fig. 37.—Screw-crease.
Single creases (Fig. 36) are for marking in places where neither the screw-crease nor the compasses can go, as for instance, in the centre of a large piece of leather or wide strap. They are also used to mark thick and heavy loops, for which purpose they are heated before using.