Essentials of woodworking

by Ira Samuel Griffith

Fig. 73.

Fig. 74.

To insert a bit, hold the brace firmly with the left hand, revolve the crank until the jaws are opened far enough to allow the bit tang to pass entirely within so that the ends of the jaws shall grip the round part—the shank of the bit. Still firmly holding the brace, revolve the crank in the opposite direction until the bit is firmly held. [Fig. 74].

37. Center Bit.

—The old fashioned center bit, [Fig. 75], is still used by carpenters for certain kinds of work. It has, for the most part, given way to the more modern auger bit.

Fig. 75.

38. The Auger Bit.

—The auger bit, [Fig. 76], is used for all ordinary boring in wood. The action of an auger bit is readily understood by referring to [Fig. 76]. The spur draws the bit into the wood. The two nibs cut the fibers, after which the lips remove the waste, later to be passed along the twist to the surface.