(1) Paring Chisel. A paring chisel (Figure 2-17) is used for shaping and preparing large surfaces. It is used with a steady sustained pressure of the hand and should never be driven with a mallet.

(2) Firmer Chisel. The firmer chisel (Figure 2-18) is more substantial tool than the paring chisel. It is usually used for routine work, but may be used for paring or light mortising. When paring, drive the chisel by hand pressure. For light mortising, use a mallet.

(3) Framing Chisel. A framing (or mortise) chisel (Figure 2-19) is a heavy-duty tool, which is used for heavy work. These chisels have an iron ring fitted to the end of the handle to prevent splitting when it is struck with a heavy mallet.

(4) Slick Chisel. Any chisel having a blade wider than 2 inches is called a slick chisel. Regular sizes range from 2 1/2 to 4 inches. They are used on large surfaces where there is considerable material to be removed or where unusual power is required.

(1) Replacing the Wood Chisel Head. A wood chisel with a mushroomed head (Figure 2-20) should be replaced immediately, because a mallet can glance off its mushroomed surface easily and spoil the work surface or cause injury.

(2) Whetting the Cutting Edge. The cutting edge of the wood chisel can be kept in shape by whetting it on an oilstone (Figure 2-21), unless its edge is nicked or the bevel has become too rounded with careless whetting. In this case, the chisel must be ground, taking care the bevel is ground straight. Keep the length of the bevel about two times the thickness of the unbeveled part of the blade.

(3) Grinding a Wood Chisel. To grind a wood chisel, first square the cutting edge. To do this, hold the chisel at a right angle to the grinding wheel with the bevel up and move it from side to side (Figure 2-22). Dip the chisel in water frequently to avoid loss of temper. Check the edge with a small square to be sure the edge is at a right angle to the sides of the blade.

(4) Restoring the Bevel. To restore the bevel, readjust the grinder tool rest to a position that will give the chisel the correct bevel (usually 30 degrees). Hold the bevel lightly against the wheel (Figure 2-23) and grind with the same side-to-side motion used in squaring the cutting edge. To avoid loss of temper, cool the chisel by dipping it in water during the sharpening process.

(5) Grinding and Honing. Figure 2-24 shows a properly ground and properly honed chisel. Remember X should equal twice the width of Y.