A small surface-plate about three or four inches across is easily made of steel, and forged instead of cast. After the steel is cut to its length, it is trimmed with a chisel, to prevent the rugged pieces being hammered into the work ; and after a smoothing with a flatter and a softening with slow cooling, the plate is ready for planing.

Where a steam-hammer large enough is on the premises, it is advisable to forge the larger plates also, and the material used should be a cheap cast steel, which is now attainable. By forging a large surface-plate all risk of making a spongy casting is avoided. When a plate is to be made by forging, the steel should be cast in a mould about the same shape as the intended forging when finished, but it should be larger, to admit a steam-hammering; this hammering is given as soon after the pouring as convenient, to avoid the reheating in a furnace. Surface-plates require a granular or crystalline form for the particles; so that only a small amount of hammering is given to the work, the amount being sufficient to condense the mass without producing fibres.

Surface-plates and tables of several feet in length and width are cast to their intended shapes, some having a number of slots and holes in various sides, to render the tables suitable for their special work. A surface-plate termed a bench-plate is one used near vices, and is kept on or near a vice-bench. Such a plate is frequently moved from place to place, and two handles are provided to screw into holes in the plate's edges when it is necessary to carry it about. To avoid the plate's tendency to bend with its own weight, a hollow is formed at the time of casting in the back of the plate; this recess is at the middle, which is the portion furthest from the plate's edges, and therefore needs to be made as light as possible, because while in use it is without any prop or support, except the adjoining metal. Large tables, which are made by casting without any forging, are made strong and light by means of recesses and ribs that are formed at the time of pouring; and if only one side of the table is to be specially planed, this one side is at the bottom of the mould, the bottom of the work being the most solid portion.

A cheap class of plates are those formed of the superfluous cakes or slices which are cut off a shaft while in a lathe. A surface-plate made by such means is lathe-turned on both sides while still attached to the shaft, but partly cut off with a parter; after being smoothed with turning to as near the centre of the shaft as possible, the piece is broken off, and the rugged portions which remain at the middle are planed off with a shaping-machine or planing-machine. By this means a small quantity is taken off both sides of the plate, in addition to cutting off the rough pieces at the middle.

Pillar-tables are those which consist of pillars that have one end specially smoothed and planed. One of these implements is stood in some convenient place, with its plane extremity upwards, and at a proper height for its special use. These tables are of different heights and diameters, and the simplest sort consists of either a short bar or rod of iron which is lathe-turned at one end and smoothed with scraping to produce the required surface. Pillar-tables are not liable to distortion in their plane surfaces while being moved about, or through their own weight; so that such a tool is specially useful when a particularly good surface is required. Such a table, if cast, may easily be made ornamental by carefully designing the shapes of the wood patterns. A simple class of such implements are denoted by Fig. 514, and are made of either wrought iron or cast steel. Another class which may be made of cast steel or cast iron are indicated by Fig. 515. Pillar-tables may be tightly fixed in the ground if not intended to be portable, and loosely stood on any floor when they are to be capable of being moved about.

The methods for planing surface-plates after being cast or forged, include grinding on a grindstone, chipping with hand chisels, turning, planing on a planing-machine, filing, and scraping. A small steel or cast-iron plate, that is only a few pounds in weight, is first ground by gripping it in tongs and holding it to a grindstone well supplied with water. After all the outer hard skin is thus taken off, the work is next turned with a lathe, or flattened with a planing-machine, until the plane surface or surfaces are produced. Small plates should be forged or cast of a proper size, to avoid all reducing, except by means of a grindstone and filing ; such a course is especially necessary for a maker who is not furnished with planing-machines. When it is necessary to reduce a surface with chipping-chisels, the edges are first bevelled, and a number of grooves, or channels, are next made across the surface with a grooving chisel, having a cutting part about a quarter of an inch wide; after which the ridges thus formed are cut off with a planing or smoothing chisel. A plate grooved by this mode is denoted by Fig. 521. Lathe-turning is a convenient process for reducing a surface-plate which is circular. To-and-fro shaping-machines are used for planing small plates which are rectangular, and all large surface-plates or tables of several feet in length are reduced to their proper dimensions with large planing-machines.

When any one of these processes is in operation, the roughing of the entire work should be finished before the smoothing of any part is commenced. During the chipping, turning, or planing of any surface-plate, it is necessary to take off the outer hard skin of every side of the work which is to be reduced, and also to reduce the entire piece of work to very near its finished dimensions, previous to completing the planing or turning of any one side. By this method the work is put upside down and otherwise shifted several times during progress, because each side which is to be reduced is fixed twice to the lathe-chuck, or other machine-table employed for the purpose. By such modes of reducing, the work is not bent nor any of its smooth sides bulged after being smoothed, which will happen if a rough side is reduced after a smooth one is finished. This bulging is caused by the metal being harder and more elastic on one side than at some other side or place in the work, and also by the friction of the tool heating the work and expanding it, and through one side of a casting being cooled too soon ; also through hammering one side of the plate more than the opposite side while finishing the forging, and other causes. Previous to each fixing, the work may be tumbled about, stood on its corners, and hammered in several places, which further tends to promote a sort of permanent relation of the particles, which will not be liable to disarrangement by the future usage of the table. After the work is properly reduced on all sides, the final cuts given are very thin; and during the finishing cut of any side the work is but lightly held with only a gentle pressure of the fixing bolts, every bolt or other fastening being loosened after all the rough cuts.

In the course of planing or other reducing of a surface-plate, the work may be condemned through the appearance of spongy portions. If these are not numerous, the defects are remedied by plugging. To fill up a spongy place, the proper materials are gun-metal, iron, and steel. If a hole about half an inch in diameter is situated near the middle of a surface, the hole is put into a proper shape with chiselling and filing, the bottom of the hole being made a little larger than the mouth, and the edges around the mouth being thickened and smoothed. When the hole is ready, a plug of red-hot iron or steel of proper length is hammered into the hole until the outer extremity of the plug is about an eighth of an inch above the surface; about a sixteenth of this eighth is next chiselled off, and the plug allowed to cool. When cold, a final hammering is given to make the plug fill the entire recess; after this final riveting, the plug must not be chiselled or hammered in any way, but is reduced with planing and filing until level with the surface. To fill a hole situated near one edge of a surface, a small portion may be chiselled out to enlarge the opening until shaped to a dovetail form; after which, a piece of metal is tightly fitted into the opening, and also riveted a little to fill up all interstices. When several sponge-holes are discovered near together and near an edge, all of them are enlarged to form one large opening, which is next dovetailed and a piece fitted to the opening in the mode described.