The hand-shaping of such articles as rectangular blocks, keys, and surface-plates, is shown by Figs. 797, 798, 799, 800, and 802. Blocks or plates which require well-formed corners and edges should, in all cases, be bevelled, previous to chipping, in order to prevent irregular breakage. Such bevelling is indicated in Fig. 797, and is done by either rough filing or grinding. After bevelling, grooves are next formed, by chiselling, similar to those seen in Fig. 798, which prepares the piece for reducing with a planing-chisel, as described for other Avork. If the bevelling of the block has been carefully done to the straight gauge-lines which are marked to show the place of the desired plane, the subsequent chipping with chisels will be also properly done, because the lines which constitute the junctions of the bevels with the block are those to which the operator works, instead of to the rugged superfluous metal.

Fig. 799 represents a surface plate which is bevelled in the mode just mentioned, and a similar plate, after bevelling and grooving, is shown by Fig. 800. The method of holding a small plate or block while being chiselled consists in gripping it in a vice, if the piece to be held is not too large; but, if so, it is laid upon a bench, or stood edgeways on the floor, or on wood blocks of suitable height, in which position it may lean against a bench, as indicated by Fig. 825. A plate which is heavy enough will thus stand while being filed and chipped, without any further fastening ; but, for security, it is proper to place one or two heavy objects in front of the plate, or to drive in one or two wedges between the bottom edge and the floor.

In the Figure 798, the series of grooves are shown to be parallel to each other, and extending across the object in one direction only. Such grooves are suitable if the surface being reduced is only about six or eight inches across; but for larger surfaces another series of preliminary grooves should be made across, and at right angles to, the set first made. There is considerable advantage connected with such grooving, because the operator is thereby enabled to see plainly where he is chipping, and is not liable to drive the chisel too far into the metal, if the first series of grooves were carefully formed. This first set becomes a sort of guide or gauge by which the second set are easily and quickly made; therefore the means of knowing how deep to drive the chisel at any particular place of a groove during the first grooving, must be remembered. If a side of a plate or block is a plane previous to reducing it, and it is decided to make the object a quarter of an inch thinner, it is evident that the slice cut off must be exactly a quarter of an inch thick in any part of it; therefore the operator, while chipping such a piece, would carefully observe the chisel and prevent it entering the metal further than a quarter of an inch. But if a rugged piece requires reduction by chiselling, the surface must be examined, previous to chipping, to ascertain whether it is concave or convex, and to what extent. With this intention, a straight-edge is applied in various directions and in several places across the rough metal, and the extreme depth of the deepest concavity that may exist is thereby known. This hollow, and also any others that may be of consequence, are marked by chalking them, which will result in directing attention to them while chipping. If it is found that the rugged surface is convex in a few places, instead of concave, the prominences are chalked, and also chiselled off, previous to chipping the entire surface.

After the general condition of the rugged exterior is ascertained, and the edges bevelled to denote the required dimensions, the grooving proceeds, during which operation the amount of care necessary depends on the distance across the surface; the greater the distance, the greater is the care required, through the workman not being so able to guide the chisel and generate a large plane of three or four feet across, as to guide it in a plane of only an inch across.

During the grooving, a straight-edge must be frequently applied to the bottom of each groove, in order to discover whether it is tolerably flat, and also whether it is parallel to the desired plane, the boundaries of which are indicated by the scribed lines at the bottoms of the bevels.

By these remarks it will be seen that if due care is exercised at the first grooving, in order to make the bottoms of all the first set parallel to the plane which is to be produced, the making of the second set will be comparatively easy, because these can be formed accurately by looking to the bottoms of the first grooves while cutting. It will be also a very easy and straightforward operation to cut off the small four-sided projections which are left remaining after the second series of grooves are made. These portions are quickly removed with a planing-chisel, and without the need of applying any straight-edge until the entire surface is chipped and is ready for filing. The cross-grooving here referred to, is represented in Fig. 800.

The piece shown by Fig. 802 is a portion of steel or iron bar which is to be made into a taper key by chiselling. Such a piece is first lined to indicate the intended dimensions and shape, and next grooved as seen in the Figure, the deep grooves being only partly formed at the first grooving, to allow a planing-chisel to be used for cutting off the superfluous ridges without the risk of breaking off too much metal.