Plummer-blocks or pillow-blocks are usually of cast iron, and are required for supporting axles of various classes during their rotation, the gap in a pillow-block being required to contain the bearer-brasses which are in direct contact with the axle-bearing or neck.

The first planing of a plummer-block should commence with regard to a centre-line; this line is marked on one broad side of the block across its gap, and extends across the intended centre of the brasses, or across the axis of the axle. From this line, considered as a primary, the distance to the bottom surface of the block is marked, if it can at that time be assertained by scribing a line along one edge of the bottom of the block. The distance from the centre line to the top of the block is also marked by scribing a line at the top edge, this line being parallel to the one at the bottom. After marking, the portion first planed should be the bottom, and the fixing for this purpose is effected with poppets, and with holding plates applied to the ledges extending from the block's sides. At this fixing for planing the bottom, two or three wedges are put beneath the rough portions near the table, to place the broad sides of the block at right-angles to the table. Those blocks which are without any ledge, are sometimes drilled at opposite ends, that two short pieces of iron may be put in to sustain the paws of holding-plates. The block may be held also by means of clamp-plates, as seen in Fig. 751. After the bottom is planed by some means, and the adjoining edges also planed, it is put upside-down, and placed with its planed bottom in contact with the table, and in this situation it is again fixed in order to plane the top and broad sides, or if not entire broad sides, to plane the ledges which surround the edges of the block's gap. At this fixing, the length of the block is parallel to the direction of the table's motion, as denoted in Fig. 752, the bottom planed edge of the block being made to coincide with one of the usual straight gauge-lines on the table. This line is shown by L in the Figure, and a rapid adjustment is effected thereby, which prepares the block for being planed on both its sides at right-angles to the table, and also for planing the top, which is reduced to the line scribed for the purpose. By these processes, three or four blocks may be fixed at one time on the table, whenever several of the same shape and dimensions are in progress.

After the bottom, sides, and top of a plummer-block are planed, it is ready for the planing of its gap-sides. These surfaces of a block, or of a number of blocks, are planed while the blocks are arranged in the position indicated in Fig. 754. Previous to fixing for shaping the gaps, each block requires a line to be scribed on one of its planed broad sides; this is the intended centre line of the gap. and it is at right angles to the block's bottom surface, extending from the bottom of the gap to the extreme edge of the bottom, which is in contact with the planing-table. In addition to this line, the intended shape and depth of the gap is marked on the side, either by means of a sheet gauge termed a templet, or by fixing a piece of wood in the gap, and scribing with a straight-edge and scriber. If a piece of wood is fixed in, the centre line on the metal is made to extend along the wood to the top of the block, so that the gap's sides may be marked at right angles to the bottom. When a sheet gauge is used for such scribing, it must be provided with a centre line, which is analagous to the line on the block; and when scribing is performed, the gauge must be so placed that the two lines are in the same straight line or in line with each other.

The blocks being properly marked, they are properly adjusted on the table by the aid of its right-angular lines. Three or four of the short lines across the table are used, the number depending on the number of blocks, and one of the long lines also is required. To this long line the centre lines of all the blocks are adjusted, and the short gauge-lines are those to which the bottom planed edges of the blocks are adjusted, thereby securing, with certainty, a right-angular position for the intended gaps with the blocks' broad sides. A block thus adjusted is indicated in Fig. 754, the line across the table being shown by L. If only one block is to be planed, it is not requisite to place the centre line on its broad side to a line along the table, because the cutting tools can be made to cut while the block is situated on any part of the table ; but to plane several blocks together, all must be fixed with regard to one long gauge-line, in order that all the gaps may be centrally situated in the blocks when planed.