Of the several kinds of bits the auger bit shown in Fig. 129 is best adapted for general use. These bits are usually had in sets of thirteen, varying by sixteenths in size from one-fourth inch to one inch, The boxes usually have a place for a three-sixteenths size, and for small work this size is quite useful. Auger bits vary greatly in price. The best are the cheapest in the end.

Do not attempt to sharpen your bits until you have had personal directions for doing such work. A good bit is easily spoiled by a little improper filing. Never use a good auger bit when there is any liability of its coming in contact with a nail or a bit of sand or grit.

The Forstner bits are exceptionally useful in boring end grain. They make smooth holes and do not split the wood. Fig. 130 illustrates one of these bits.

There are many other styles of bits. The twist drill shown in Fig. 131 is especially useful in repair work as it is not injured by coming in contact with nails. These drills are quite hard and may be used in drilling metal. They are very easily broken and must not be used except where they can be held firmly and kept from binding. The work should be so firmly held that the drill will not be broken in withdrawing from the hole or by the piece moving while drilling.

Fig. 129. Auger Bit. A, Nibs; B, Spur; C, Lips.

Fig 130. Forstner Bit.

Fig. 131. Twist Drill.

The twist bit (Fig. 132) is similar to the twist drill but not so hard and consequently not so easily broken. It is not hard enough to drill nails without injury. It is useful in boring deep holes for screws.

The gimlet bit is tapering as shown in Fig. 133 and is a good shape for boring holes for short, blunt screws.

The German bit is also a good bit for boring small holes. You see by referring to Fig. 134 that this bit has but a single twist and therefore presents a sharper edge to the wood than the common gimlet bit.

Fig. 135 is of a center bit, a very cheap bit and a good bit for rough work and for boring soft wood. Such bits are easily sharpened and are used by many where an auger bit might be spoiled.

Fig. 132. Twist Bit.

Fig. 133. Gimlet Bit

Fig. 134. German Bit.