Brace and Bits.—There are various kinds of braces on the market, but the more generally used are the two following: A wooden brace with brass mountings is shown at Fig. 104. It is better to buy the bits fitted to this brace, as they are more truly centred than those bought separate are likely to be, and the centering of the bits is essential to their proper action. With the American pattern brace (Fig. 105) this is not necessary, as by turning the socket
Fig. 99.—Bradawl.
Fig. 100.—Twist Gimlet.
Fig. 101.—Shell Gimlet.
Fig. 102.—Twist-nose Gimlet.
Fig. 103.—Auger Gimlet.
the jaws are expanded or contracted so as to grip the shank of any size bit. This kind of brace may be had with a ratchet movement, which is very useful for boring or turning screws in corner positions where a complete revolution is not possible. Bits are known in very numerous forms. The pin bit is like a gouge sharpened both inside and outside; when its corners are removed, it becomes a shell bit suited for boring at right angles to the fibre of the wood. The spoon bit resembles the shell bit, but is pointed; it is found to work easily, freely, and well. The nose bit is of similar shape, but its cutting edge is a part of the steel bent nearly to a right-angle and sharpened to form a kind of chisel; this tool is efficient for boring the end way of the grain, but not across the grain. The twist-nose bit or half-twist, or Norwegian bit, is exactly of the shape shown for the twist-nose gimlet by Fig. 102; it screws itself into the wood, and the chips tend to rise out of the hole. It is found to split narrow strips of wood, but it answers well for all other purposes. All the above bits can be obtained in a great variety of sizes; but exact size is not guaranteed by the dealers, and the best plan is to bore a hole and measure, rather
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| Fig. 104.—Wooden Brace. | Fig. 105.—Steel Brace. |
than measure the bit. Holes are enlarged by means of a hollow taper bit. Patent twist bits (Fig. 106) having a screw centre are known as screw bits, and these bore well in any wood and in any direction, relieving themselves of the chips and cutting
Fig. 106.—Gedge's Twist Screw Bit.
true to dimensions. Centre bits are perhaps the most commonly used bits (see Figs. 107 and 108); they are useful for boring large holes, and are much superior to shell type bits in the important point of boring exactly where the hole is required. Expanding centre bits (Fig. 109) are known,
