The brittle character of steel generally, does not prevent piston-rods, small and large, being made of it, for several reasons; among which are their comparative lightness and favourable arrangement of the constituent particles, and their greater capability of resisting the destructive abrasion resulting from the friction of the packing in the packing-box ; also because the amount of power absorbed and wasted by friction is small, the area of the rod's friction surface being comparatively small; and because manufacturers are now commencing to make a strong tenacious steel that meets the requirements.

Small piston-rods may be forged with T-ends large enough to constitute guide-blocks, so that the rod, crosshead, and guide-blocks together constitute one forging only. To make a small rod of this character, a bar of iron or steel is selected, or drawn down until its width is about the same dimension as the length of the intended crosshead or T-part. A pair of fullers is then driven in at the junction of the crosshead and cylindrical part of the intended rod. The thick lump that remains is then reduced by hammering until the forged diameter is attained; or two pieces may be cut off, leaving the rod between, if the economy of metal is not at that time being considered.

Large piston-rods with T-ends need a more economical method. To avoid the lengthy process of reducing, or the wasteful method of cutting off, the T-part is formed by splitting open, the end of a bar and upsetting it until the necessary right-angular form is obtained.

At the place intended to be the outer extremity of the T-piece a round hole is punched. A slit is next made from the hole to the extremity of the bar by driving chisels half way through from both sides, the length of the slit being equal to the distance of the hole from the extremity. A thick wedge in a handle is next driven into the slit to partly open it, and the two ends thus produced are afterwards opened to the necessary distance by sledge-hammering sideways while the work is across the anvil.

Upsetting is next performed to produce the flat bottom or bearing of the T-piece. For small work this upsetting is done by two methods, one of which consists in putting the work into a heading-tool and flattening the head by hammering; and the other plan is to place the T-part upon the anvil and shape the work by striking the upper cold end. When the rod is too long for the anvil, the upsetting-block, whose top is level with the ground, is preferable to the anvil. Upsetting the-T-piece of a large rod is performed by striking or battering the end with a pendulum-hammer.

During these upsetting processes the iron is at welding heat; if steel is being used, the heat is as great as the character of the particular piece of metal will allow.

After the head or T-part is sufficiently upset, and its proper length, width, and thickness attained, the part of the rod next adjoining is reduced by fullers to the desired forged diameter; tongs are then fixed to the T-part, and the lump for the cylindrical portion is welded, reduced to proper dimensions, and well closed by angular-gap tools, the smoothing of the work being effected by half-round tools.

The final process is straightening the round part with half-round top-tool and sledgehammer, or steam-hammer, and adjusting the T-end to a right angle with the length of the rod. For this purpose a long straight-edge and a square are needed. The straight-edge is applied to several sides of the round part of the rod to discover the hollow places; these places are put next the anvil-top while the upper sides of the rod are driven down by hammering. After the round or cylindrical portion is sufficiently near to straightness, the T-part is adjusted to a right angle by being struck with a pendulum-hammer, or by a sledge-hammer if the work is not too large.