A great variety of small wheels, not more than six, eight, or ten inches in diameter, can be easily and accurately bored in wood chucks. A wheel which is bored in such a chuck will have its hole exactly concentric with the rim, but not with the boss, unless the wood chuck is specially shifted for this purpose, after the wheel is put into the chuck.

The piece of wood to be made into a chuck is fixed to a cast-iron disc-chuck of the lathe in the same manner as shown in Fig. 1018 for holding a gland; and when firmly fastened, the hole in the middle is truly and smoothly turned to fit tight around the rim of the wheel to be bored. During the process it is necessary to consider whether the axis of the hole is to be right-angular to the arms, or to the rim, in case the arms may not be parallel with the rim, as before mentioned. When it is decided which is to be square to the hole, either the arms or the rim is considered to be a sort of primary base or plane which must be put parallel with the chuck. Therefore a bearing surface is accurately formed by turning in the hole of the wood chuck. If it is desired to place the wheel-rim parallel with the chuck, the wood at the middle is cleared out to allow ample room for the boss to extend inwards, and a smooth true surface is turned adjoining the extreme boundary of the hole which fits the rim. But if the arms are to be placed parallel, the wood must be cleared out to allow both boss and rim to extend inwards, without bearing upon any surface, thus forming two circular recesses, one for the wheel-boss and the other for the rim. If the chuck is now accurately bored to fit the extreme outer circumference of the wheel-rim, the wheel can be driven in, and when in its place, the arms will bear upon the truly turned surface of the wood, and the rim will be firmly gripped by the wood around its outer surface, usually termed the edge.

Wood chucks are particularly useful for boring wheels which are cast without any hole in their bosses, and which are too small to need a preliminary boring with a driller. Disc-wheels are easily held, and should be bored in wood chucks, especially if cast without any hole in the bosses, and consequently in a condition to prevent the insertion of a centre-bolt until drilled.