Steam hammers are industrial grade power hammers and would have been found in commercial manufacturing. According to Douglas Freund (Pounding Out the Profits, p 4.), “Steam hammers had begun to assume a prominent place in English and French forges during the 1840’s.”

       Below is some steam hammer information from Marvels of Science and Industry  from the International Exhibition (Centennial Exhibition) 1876 Philadelphia. Book by Joseph M. Wilson, 1880, printed New York, pp. 129-134. Be sure to click the links in the text to see illustrations of the English steam hammers.

       MESSRS. B. & S. MASSEY, of MANCHESTER, ENGLAND, make a fine exhibit of STEAM HAMMERS, which present some peculiarities of design different from the usual steam hammer, and appear to operate with great efficiency. They are double-acting and work without jar or shock, giving blows dead or elastic, and of any degree of intensity, rapidity of action or length of stroke desired, the larger hammers being controlled generally by hand, and the smaller ones arranged so as to work both self-acting and by hand. The action is therefore completely under control, and can be varied according to the kind of work to be done. - Generally with self-acting hammers there is great difficulty in obtaining the heavy “dead” blow so often required; but in these, by means of a hand-lever connected directly with the valve, the hammer may be changed instantly from self-acting to hand-working, and perfectly “dead” blows delivered at any time without the least delay. Their small hammers are particularly intended for smiths’ work, being applicable to the lightest kinds of forgings, such as usually done by hand, and their use is rapidly replacing that of handwork, resulting in great economy of labor, fuel and material even in the smallest smith-shops. The hammer shown by Fig. 1 is of a class comprising several sizes, and exceedingly convenient and easy to operate with, allowing ready access on three sides, and, owing to the double standards on the fourth side, with opening between them, permitting long bars to be worked on the anvil in either direction. The arrangement for working the valves in these hammers, as already stated, is a combination of self-acting and hand-worked gearing, and it is different from that ordinarily employed, being without the usual cams or sliding-wedge. As the hammer rises and falls when in action, a hardened roller on the back of the head slides on the face of a curved lever, which rotates about a pin near its upper end, and is held by a spiral spring always in position against the roller. At every movement of the hammer this lever operates a valve-spindle and regulating-valve, the length traveled by the hammer being controlled by another lever attached to the fulcrum-pin of the curved lever, and by which this pin may be raised or lowered by hand, and the points at which the steam is admitted or allowed to escape varied at pleasure. A guardplate and catch permit this governing lever to be fixed at any point desired. The regulating-valve is hollow through the centre, being really a double piston open at both ends, with a number of ports for the steam to enter and escape, arranged all around on the sides, and holding it in perfect equilibrium. The ports open and close very quickly, and allow great rapidity and force of action to the hammer, as many as two hundred and fifty blows per minute being struck with a pressure of from forty to sixty pounds, with the length of stroke entirely under command from a few inches to nearly two feet, and variable without checking the machine.
       Ramsbottom’s Steel-packing Rings are used on the hammer-piston, which is forged in one solid piece with the rod, and the head is of hammered scrap-iron. The anvil-block is a heavy casting made separate from the base and turned to fit a bored hole in the base plate so as to assure its being kept to its true position.
       Fig. 2 represents a light hammer, only a half hundredweight, intended for forging files, bolts, cutlery, etc., and operating with a foot-treadle, so that the workman may have both hands free for the proper manipulation of his work. The foot-treadle is omitted in some cases. This hammer has been worked up to a speed of four hundred blows per minute. Fig. 3 illustrates one of the large size hammers running up to a ton or more in weight. Fig. 4 represents a steam stamp intended especially for die-forging, and regulated either by the foot or by hand. When steam is turned on, the hammer rises to the top of stroke and keeps that position until directed downwards by the action of the operator. It then descends with a single dead blow, performing its work, and rises again into its original position, which it retains until the workman is ready for an other stroke. It is wonderful how many articles formerly so expensive are now made by die-forging, being stamped out from the red-hot iron nearly ready for use, requiring in most cases very little work to fit them up, and resulting in great saving of labor. Bolts, rivets, nuts, screwkeys, wrenches, and other tools, and even such articles as sewing-machine shuttles, are made in this way with the greatest accuracy, economy and despatch.