A great number of small works are more conveniently filed, whilst they are held with the left hand, the file being then managed exclusively with the right; this enables the artizan more easily to judge of the position of the file. In such cases, a piece of wood f, fig. 858, called a filing-block, is fixed in the table or tail-vice, and square, round, and similar pieces, are rested in one of several notches made in the block with a triangular file. If the works are rectangular, or have flat surfaces, they are held quite at rest; if they are circular, they are continually rotated, as will be explained, and if they are wide and flat, they are laid on the flat surface of the filing-block f, against a ledge or projection represented on the lower side of the block, which is then placed upwards.
Pieces that are sufficiently long and bulky, are held upon the filing-block by the hand unassistedly; but small and short works arc more usually fixed in some description of hand-vice, and applied in the position shown in fig. 858, and the vice being larger than the work, serves as a handle, and affords a better grasp.
For works of larger size the hand-vices are progressively larger, as in 859 and 860; some of them have wooden handles. Almost all the hand-vices have fly-nuts to be twisted with the fingers, but the most powerful, which sometimes weigh as much as about three pounds, have square nuts that are fastened by a key or spanner s. Occasionally, to ensure a strong grip, one ear of the ordinary fly-not is pinched in the tail-vice, whilst the hand-vice is twisted bodily round; but unless due caution is used, either the vice may be strained, or the screw broken, from the great purchase thus obtained.