Carpentry and Woodwork

by Edwin W. Foster

The plane iron and cap are fastened together with a set screw, and the cap is removed when it is being ground or sharpened on an oilstone.

Fig. 111. The smoothing plane

This set screw, which is loosened with a screw-driver, or the edge of the clamp used as a screw-driver, also allows the distance from the cutting edge to the cap to be changed for soft or hard woods. These two irons are fastened into the throat of the plane by the clamp.

Fig. 111b. The smoothing plane

The lever (1) is for straightening the plane iron, and the screw s is for adjusting the depth of the cut.

The difference between the jack and smooth planes, aside from the size, is in the shape of the "cutter" or "bit." In the jack plane, the bit is ground with a slightly curved cutting edge. This enables the tool to remove coarse shavings, but leaves a slightly corrugated surface which must be smoothed with the smoothing plane.