In the modern chisel, all the grinding is done on one side. This constitutes the essential feature of the chisel, namely, that the back of the blade is kept perfectly flat and the face is ground to a bevel. Blades vary in width from 1⁄16 inch to 2 inches. Next to the blade on the end of which is the cutting edge, is the shank, Fig. 65. Next, as in socketed chisels, there is the socket to receive the handle, or, in tanged chisels, a shoulder and four-sided tang which is driven into the handle, which is bound at its lower end by a ferrule. The handle is usually made of apple wood.
Fig. 65. Firmer-Chisel.
The most familiar form is the firmer-chisel, Fig. 65, which is said to get its name from the fact that it is firmer or stiffer than the paring-chisel. (See below.) The firmer-chisel is a general utility tool, being suited for hand pressure or mallet pounding, for paring or for light mortising.
Different varieties of chisels are named; (1) according to their uses; as paring-chisels, framing-chisels, mortise-chisels, carving-chisels, turning-chisels, etc.
Fig. 66. Paring-Chisel. Fig. 67. Framing-Chisel. Fig. 68. Mortise-Chisel.
The paring-chisel, Fig. 66, has a handle specially shaped to give control over its movements, and a long thin blade, which in the best form is beveled on the two edges to facilitate grooving. It is intended only for steady pressure with the hand and not for use with a mallet.
The framing-chisel, Fig. 67, is thick and heavy and was formerly much used in house framing. It is usually made with the handle fitting into a socket on the shank, in order to withstand the shock of heavy blows from the mallet.
The mortise-chisel, Fig. 68, is made abnormally thick to give the stiffness necessary for levering the waste out of mortises.