Hammer (tool)

“ The upholsterer's hammer is an unknown; it is not dated, its maker is anonymous, as is its user. It is of American origin, yet of a style that might have been used in England or on the Continent. This lack of provenance need not detract from its significance as a material survival. This hammer, the brace (fig. 46) , the bevel (fig. 47) , and the compass saw (fig. 48) are sufficiently provocative in their design to conjure some image of a technology dependent upon the skilled hand of craftsmen working in wood and of the relationship between the hand, the tool, and the finished product. ”

“ A stone hammer found at Claycrop, Kirkinner, [5] Wigtownshire, is by the courtesy of the Society of Antiquaries of Scotland, shown in Fig. 145a. In form, it is very like Fig. 136a from Wick, but blunter at the edge.
The instrument shown in Fig. 146 is perhaps more like a blunted axe-hammer than a simple hammer. It has at one end a much-rounded point, and at the other is nearly straight across, though rounded in the other direction. It would appear to be a weapon rather than a tool. ”

“ Fig. 35.—Marking Gauge in Use.
34. The hammer (A.) is used by the average wood-worker more than any other tool. The “face” (Fig. 36, a) and the “claws” (b) should be tempered carefully, as they will either bruise or bend if too soft, or [Pg 64] break if too hard. The eye (c) is made longer than it is wide, to prevent the head from turning on the handle, and larger at the outside of the head than it is at the neck, so that the handle may be firmly wedged in the eye or socket. The neck (d) , by extending upon the handle as it does, adds much to the strength of the connection. ”

“ In fitting the handle, care must be taken that its oval is made to stand true with the oval of the tool eye. Especially is this necessary in the case of a hammer. Suppose, for example, that in Fig. 2107 the length of the oval of the handle lies in the plane a b, while that of the eye lies in the plane c d, then the face of the hammer will meet the work on one side, and the hammer will wear on one side, as shown in figure at e. If, however, the eye is not true in the hammer, the handle must be fitted true to the body of the hammer ”

“ His first hammer of this kind was 120 lbs. in weight; it was raised eight inches before making each blow. Watt afterwards made a tilt-hammer for Mr. Wilkinson of Bradley Forge, of 7 1/2 cwt., and it made 300 blows a minute. Other improvements were made in the hammer from time to time, but no material alteration was made in the power by which it was worked until Mr. Nasmyth took it in hand, and applying to it the force of steam, at once provided the worker in iron with the most formidable of machine-tools. ”

“ A curved spring held them up to the cross-bar when the weight of the hammer was removed. Between the 6-inch cross-bar and the tool-holders and the hammer faces I introduced a sheet of heavy leather belting, which deadened the force of the blow. A stone-cutter uses a wooden mallet to drive the tooth-chisels and droves, because the impact of iron on iron has a disintegrating effect upon the stone, which the stone-cutters call “stunning the stone.” ”

“ The hand-hammer has always been an important tool, and, in the form of the stone celt, it was perhaps the first invented. When the hammer of iron superseded that of stone, it was found practicable in the hands of a "cunning" workman to execute by its means metal work of great beauty and even delicacy. But since the invention of cast-iron, and the manufacture of wrought-iron in large masses, the art of hammer-working has almost become lost ”

“ Just so the owner of [203] an automobile learns more about mechanics and the construction of his machine by being obliged to make repairs on the road, miles from any repair shop, and with a limited number of tools and appliances.
THE HAMMER
Fig. 130. Hammers
This common tool is made in at least thirty different forms, and some styles in nine or ten different weights. For woodwork, the adze-eye claw hammer, weight sixteen ounces, will answer all requirements. For use with brads as small as 3⁄8 inch, a brad hammer of three or four ounces is desirable. ”

“ When using this form of enrichment, the stone should never appear to rise abruptly from the primary mass, but should be approached by a series of rising planes.
Planishing
9. The process of smoothing and, at the same time, hardening the surface of the metal with a steel planishing hammer. The hammer strokes give an interesting texture to the surface which may be varied, from the heavily indented to the smooth surface, at the will of the craftsman. The more obvious hammer strokes are not to be desired as they bring a tool process into too much prominence for good taste. ”

“ A rectangular piece of metal is cut out about 1/2 inch larger on all sides than the design calls for and given a hammered surface with the pein end of a large hammer. After the design has been transferred to the back of the metal, it is then placed on pitch face down, and with a suitable tool the lines are sunk at A and B, Plate 31, about 1/16", as shown in the section at C. It is then removed from the pitch and, after cleaning, is put over a sand bag face up, and with a rawhide hammer, the part that is to serve as a reflector is concaved a little. ”

“ The process is the same as the one used for carbon steel, heating to a red heat and covering the piece with slacked lime until cold.
In cutting high speed tool steel, the bar may be nicked with the emery wheel, then broken.
[82]
In working tool steel or iron of any weight the blows of the hammer must be heavy. Light blows stretch the outer part of the metal and not the center. This is liable to fracture it. The blow must be heavy so as to penetrate thru the bar. A trip hammer of ordinary size run by a belt is a very economical tool for the school shop. ”

“ When the use of iron extended and larger ironwork came to be forged, for cannon, tools, and machinery, the ordinary hand-hammer was found insufficient, and the helve or forge-hammer was invented. This was usually driven by a water-wheel, or by oxen or horses. The tilt-hammer was another form in which it was used, the smaller kinds being worked by the foot. Among Watt's various inventions, was a tilt-hammer of considerable power, which he at first worked by means of a water-wheel, and afterwards by a steam engine regulated by a fly-wheel. ”

“ The various parts of the wheels are produced in quantity either by rolling or by dies under the hammer; these parts are brought together in their relative positions in a mould, heated to a welding heat, and then by a blow of the steam hammer, furnished with dies, are stamped into a complete and all but finished wheel. It is evident that wherever wrought-iron articles of a manageable size have to be produced in considerable quantities, the same process may be adopted, and the saving effected by the substitution of this for the ordinary forging process will doubtless ere long prove incalculable. ”

“ Pliers
A blow from this tool does not shatter the tool handle as would a blow from a hammer. A comparison of the two blows might be likened to the action of gun powder and dynamite. The slow burning powder represents the action of the mallet. The hammer should never be used on a chisel or gouge.
Hand screws for holding glued-up work together, sometimes for holding special work on the bench top, are made of wood, with either wood or metal spindles. For ordinary work, the jaws [201] should be parallel, but special forms are on the market which will hold irregular forms, as shown in Fig. ”

“ These, with the primitive hammer, formed the principal stock-in-trade of the early mechanics, who were handicraftsmen in the literal sense of the word. But the work which the early craftsmen in wood, stone, brass, and iron, contrived to execute, sufficed to show how much expertness in the handling of tools will serve to compensate for their mechanical imperfections. Workmen then sought rather to aid muscular strength than to supersede it, and mainly to facilitate the efforts of manual skill. ”

“ In such cases, the workmen acquire great skill and expedition in the manufacture. A tilt hammer is often used in forging large masses of iron, and even in making utensils as small as the hoe, the axe, and the sword; but the hammer which may be employed bears a due proportion in its weight to the mass of iron to be wrought. In all cases in which a tilt hammer is used, the bellows from which the blast proceeds is moved by water or steam power. ”

“ The inter-collegiate rules which govern the throwing of the hammer require that the hammer-head shall be a metal sphere; and the handle may be of any material. Up to within three or four years the handle used to be made of hard wood, but recently athletes have shown a preference for a flexible steel handle. The combined length of the head and handle must not exceed four feet, and the combined weight must be sixteen pounds. The hammer is thrown from a circle seven feet in diameter. ”

“ The labor saved by this hammer is immense. One man sits perched up on the frame to direct it, and another stands below to guide the iron on the anvil. The great long bar, white with heat, is pulled out of the furnace, laid on the massive piece of iron under the frame, and, with a dull, heavy sound, down conies the hammer, swiftly or slowly, according to the wishes of the director. From the forge and the foundry the "rough-hewn" iron-work passes to be planed, and its surface to be made "true." ”

“ There is hardly any talking in the room; the work is urgent, the hour late, so the men hurry on in silence. Here a group of grimy blacksmiths are dragging a huge white-hot iron bar to be hammered; there a row of them bend and raise themselves as under a command over their vices. Opposite them the turners bend to watch the revolving work in the machines. Sparks fly from under the hammer. From time to time an order or a curse is heard. Sometimes the hammering and filing slackens down, and then the mournful groan of the bellows blowing on to the furnaces begins. ”

“ In order to accomplish this stretching as rapidly as possible it is necessary to use a light hammer, with sufficient force to be expended in condensing the metal at its surface, and to so form the hammer that it shall expend its force upon the work with a dead blow, that is, with as little rebound as possible. These results are best accomplished with a ball pened hammer, such as shown in Fig. 2108 and weighing about 1⁄2 lb. The blows should fall dead; that is, the hammer should fall, to a great extent, by its own weight, the number rather than the force of the blows being depended upon ”

“ The two-pound drop-hammer falls a distance of twenty-two inches in the grooves of the vertical posts which are mortised and glued into the base, as are also the oblique braces to which are attached the bobbin, or axle, and crank, on which the cord is wound that raises the hammer. This hammer is a flat piece of iron having two pieces of wood, each four by two and one-half inches in size, cemented to it. A wire hook is attached just above, and the extended arm of the hook as the weight nears the top, meets a projecting pin, and slips the weight from the cord. ”

“ The hammer is made of high-grade steel, carefully tempered head and peen; the head is usually made cylindrical with slightly rounding face; the eye of the hammer is the center opening through which the handle is inserted. The peen of a hammer is the opposite end to the face, and terminates in a rounded or wedge-shaped point. ”

“ To prevent the shock of the hammer head being communicated to the driving gear, an elastic connection was usually formed between them, consisting of a steel spring or a cushion of compressed air. With the steel spring, the variation which could be given in the thickness of the work under the hammer was very limited, owing to the risk of breaking the spring; but with the compressed air or pneumatic connection the work might vary considerably in thickness, say from 0 to 8 in. with a hammer weighing 400lb. ”

“ Vickers in forging down the ingots in shafts, guns, or other large work. This hammer can give a squeeze of 3,000 tons. The steel seems to yield under it like tough putty, and, unlike the steam hammer, there is no jarring on the material, and it is manipulated with the same ease as a small hammer by hydraulics. ”

“ As soon as the furnace-door on one side of this hammer was opened, a large lump of scrap-iron at a white heat was lifted and then conducted by a crane on to the anvil beneath. At the same moment from an opposite furnace a long iron bar, heated only at one extremity, was by a gentle blow of the hammer no sooner welded to the mass than the head smith, using it as a handle, turned and re-turned the lump on the anvil so as to enable the steam-hammer to weld its contents into proper form. Of course there has been selected for this extremely heavy work the strongest man that could be obtained. ”

“ As the constant hammering on the head of the flatter will also cause the head to become battered, it is good practice frequently to draw out the head and lay the flatter aside to cool. This will anneal the steel and prevent crystallization, at least for some time.
23. The square-and round-edged set hammers (B and C, Fig. 10) are employed for various purposes. The former is used for making square shoulders or depressions such as could not be produced with the hand hammer alone, or for drawing metal between two shoulders or projections. ”