Cold chisel

“ The blacksmith’s set of chisels consists of a hot chisel for cutting off hot iron, a cold chisel for cutting cold metal, a hardy, which sets in the square hole in the anvil, C-chisels, which are curved somewhat like the carpenter’s gouge, and a cornering or V-chisel, in which the cutting edges are at a right angle one to the other.
The hot chisel has its edge well curved in its length, and is kept cool by lifting it from the work after each hammer blow, and by occasionally dipping it in water. Lifting it also prevents it from wedging in the work. ”

“ But so removed from public sight are the cars and locomotives that the existence of this underground railway is almost forgotten.
Tempering Chisels.
A practical mechanic communicates to the Scientific American the following: In hardening and tempering a cold chisel care should be taken to have a gradual shading of temper. If there is a distinct boundary line of temper color between the hard cutting edge and softer shank portion, it will be very apt to break at or near that line. The cutting edge portion of the chisel should be supported by a backing of steel gradually diminishing in hardness ”

“ When the chisel is cold it is reheated to harden and temper. Over-heating does not make the tool harder when cooled in water, but increases its brittleness, so care must be taken when heating. The heating must be very slow, and to a dark red, 21⁄2 inches long. The chisel should be cooled as the heat is going up. A common practice of heating the steel more than a cherry red and holding it out of the forge until the heat goes down, before dipping, is wrong. ”

“ Two classes of chisels are in common use: the framing chisel used for heavy work, such as the frames of buildings; and the firmer chisel. The framing chisel is strong and heavy, and has a handle capable of withstanding the blows of a mallet. The firmer chisel is designed for finer and lighter work without the mallet.
Fig. 30. The Framing Chisel
Fig. 31. The Firmer Chisel
Fig. 32. Proper Position for Horizontal Chiseling
The chisel must be sharp if we wish to do good and accurate work, and a cut on the hand made by such a sharp tool is liable to be a deep one. ”

“ The most peculiar, the truly characteristic feature of their bas-reliefs so far as execution is concerned, is the combination of incisiveness and looseness in their handling. We feel that the chisel, in spite of the haste with which it worked, has been strongly driven. It is not so in the case of other countries; as a rule where work is rapid it is also slight and superficial. ”

“ When finished with your chisel, if not likely to be required again at that place, it may be chopped off the handle and at your first fire the socket part can be placed in hot ashes or close to the blaze until the wood stump is so charred that it will readily scrape out, securing the screw for another time. Ice chisels are indispensable to any one trapping beaver, otter or mink, and no Indian would consider his outfit complete without one. ”

“ Being placed in a support or rack against the wall, and quite upright, a chisel—or rather, a series of chisels—are drawn across the surface in straight lines, and perpendicular, by the use of a large T-square. Every time the chisel is drawn with pressure across the varnished back of the glass a portion of the silver is removed, leaving a straight line quite clear or transparent, and, in fact, laying bare the surface of the plate glass. ”

“ Others in the collection of Mr. Robert Day, F.S.A., resemble Fig. 196 (41⁄2 inches) and Fig. 197 (6 inches) . The latter was found at Kanturk, Co. Cork.
Tanged chisels have been found, though not abundantly, in France. One from Beauvais is in the museum at St. Germain.
The socketed form of chisel is by no means common in this country; but some instruments, probably intended for use as chisels, have already been described among the socketed celts not provided with loops. These are all comparatively broad at the cutting edge ”

“ When the teeth are large, as in the Beaver, and the jaws powerful, their force is something wonderful, tree-trunks of considerable size being cut down quite easily.
Perhaps some of my readers may not be aware that the Chisel is constructed on exactly the same principle as the tooth of the Rodent animal. It is not entirely made of steel, as is generally thought. In the first place, a valuable material would be needlessly wasted, and, in the next place, the tool would not keep its edge except with infinite labour in grinding. ”

“ It is not a very broad chisel, but still it is one, and used as we use ours. But the chisel is not the only instrument of that workman. Its tongue is worth examining. It bores a hole into a tree that is dead or decaying, to look for insects whose nests are in the tree; and when it reaches the cell where the young insect is, it uses its tongue to get it out, and it suits exactly for the business. In the first place, it is so long that the bird can shoot it out three or four inches longer than the bill is ”

“ Chisels are either for paring the wood, and are used with the hand; or are intended to cut into the thickness of the wood, and are then struck with a large wooden hammer, called the mallet. The gouge is a curved chisel, used for cutting mouldings or making round edges. ”

“ The pitching tool has a wide thick edge and is used in rough dressing. Jumpers are shafts of steel having a widened edge, and are used for boring holes in hard stone. Chisels are made with edges from a quarter-inch to one and a half inches wide; those that exceed this width are termed boasters. The claw chisel has a number of teeth from one-eighth to three-eighths wide, and is used on the surface of hard stones after the point has been used. The drag is a semi-circular steel plate, the straight edge having teeth cut on it. ”

“ The single instrument which sufficed to build canoes and houses was the chisel; generally being a piece of old iron obtained from some vessel and fixed in a wooden handle. A stone mallet aided them in using the chisel; and with this simple "kit" of tools they contrived to manufacture plates, bowls, carved oars, and many ornamental things.
Like the men of all savage nations, they made slaves of their captives, and their women. The dress of the latter consisted merely of a short petticoat, manufactured from the fibre of the cedar bark, previously soaked and prepared. ”

“ A paring chisel may be ground as thin as 20°, as it does not have to stand heavy blows, and a better edge for the purpose may thus be obtained. In whetting a chisel, the bevel must be carefully maintained, and the back kept perfectly straight, like the face of a plane iron, or it will be impossible to work to a line. ”

“ Implements, which can without hesitation be classed as chisels, are rare in Ireland, though long narrow celts approximating to the chisel form are not uncommon. These are usually of clay-slate, or of some metamorphic rock. I have, however, specimens of oval section not more than an inch wide, and as much as 5 inches long, with narrow straight edges, which seem to be undoubtedly chisels. I do not remember to have seen a specimen in flint, those described by Sir W. Wilde [10] being more celt-like in character. ”

“ One can imagine the enormous anxiety and the extraordinary coolness, steadiness of hand, and skill of the man who with one tremor of the mallet or chisel might mar the greatest stone of all ages. The chisel and the steel mallet with which this delicate operation was performed are preserved at the Tower, and it is noticeable that there are only two or three dents in the chisel, showing how true and clean the strokes must have been. ”

“ This method has been generally disused, iron or wood rods substituted in the place of the rope, and a variety of augers and chisels instead of the simple chisel, with appliances for clearing [62] the bore-hole of débris. Figs. 50 to 56 show examples of an ordinary set of well boring tools. Fig. 52 is a flat chisel; Fig. 53 a V-chisel; and Fig. 54 a T-chisel. These chisels are made from wrought-iron, and when small are usually 18 inches long, 21⁄2 inches extreme breadth, and weigh some 41⁄2 lb.; the cutting edge being faced with the best steel. ”

“ A chisel (fig. 29.) is first employed, and connected to this handle by its screw at top. If the ground is tolerably soft, the weight of the two workmen bearing upon the cross bar, and occasionally forcing it round, will soon cause the chisel to penetrate; but if the ground is hard or strong, the workmen strike the chisel down with repeated blows, so as to peck their way, often changing their situation by walking round, which breaks the stones, or other hard substances, that may happen to obstruct its progress. ”

“ If you wish them to live and increase, you must chip off a bit of the rock on which they are growing. With a chisel, or even a knife, you can do it without difficulty, for the soft slate scales and crumbles under a slight blow. ”

“ The bottom of the groove was laid off with the marking gauge set at 1⁄4 inch. The wood inside the lines was removed by making a saw cut just inside the knife lines, and cutting out with a 3⁄8-inch chisel.
This led to a talk on chisels. Ralph explained that for fine work a "firmer" chisel was used, having a comparatively thin body.
There are two kinds of handles, known as "socket" and "tang." The chisels having "tangs" should never be hammered, as the tang acts as a wedge and splits the handle. Where blows are to be struck with the mallet, a socket handle should be used. (Fig. 134.) ”

“ It is a valuable example, as showing the progressive development of ingenuity in the construction of these interesting objects. He produced, also, sketches of bronze implements, various kinds of chisels, one of them socketed, in the possession of Mr. W. F. Wakeman; the other, with a tang, for insertion into the handle, like a modern chisel. (See woodcuts.) This is in the Museum of the R. I. Academy. Similar bronze chisels were found in the hoard of celts, implements and broken metal, at Carlton Rode, Norfolk, in 1844. ”

“ Every time a fresh chisel is lowered to the bottom it should be worked round in the hole, to test whether it is its proper size and shape; if this is not the case the chisel must be raised at once and worked gradually and carefully until the hole is as it should be. The description of strata being cut by the chisel can be ascertained with considerable accuracy by a skilful workman from the character of the shock transmitted to the rods. ”

“ The best chisels for doing this are those that have got, I might say, very fine points, but the handles of which are at least as small as the little finger. With this chisel, subbia, you approach to within at least half a finger of what is called the penultima pelle, the last skin but one; then you take a chisel, scarpello, with a notch in the middle of it, [277] and carry on the work further till it be ready for the file, lima, & this file again is called the lima raspa, or roughing file, or occasionally scuffina. There are ever so many sorts of this tool ”

“ In the modern chisel, all the grinding is done on one side. This constitutes the essential feature of the chisel, namely, that the back of the blade is kept perfectly flat and the face is ground to a bevel. Blades vary in width from 1⁄16 inch to 2 inches. Next to the blade on the end of which is the cutting edge, is the shank, Fig. 65. Next, as in socketed chisels, there is the socket to receive the handle, or, in tanged chisels, a shoulder and four-sided tang which is driven into the handle, which is bound at its lower end by a ferrule. ”

“ If the boards are not tongued together, the chinks between them must be well caulked by driving in string or tow with a blunt chisel, for it is not only necessary to keep out the rain but also to keep out the wind, which has great influence on the health and laying of the fowls. ”

“ Now, it is not at all likely that the unknown inventor of the modern chisel was aware of the analogy between art and nature, and would probably have been very much surprised if anyone had stated that he had borrowed his idea from the incisor teeth of the water-rat. ”

“ This form affords a firm grip to the hand, the end e being applied to the operator’s shoulder. The shape of handle for a firmer chisel is shown in Fig. 2746.
Chisels require great care both in grinding and oilstoning them, being held very lightly upon the grindstone when finishing the grinding so as to avoid as far as possible the formation of a long [II-272] feather edge. The flat face of the chisel should never be ground, as that would make it rounding in its length, hence there would be nothing to guide it in cutting straight and the value of the tool would be almost destroyed. ”

“ Weimmick as we went along, to see what he was like in the light of day, I found him to be a dry man, rather short in stature, with a square wooden face, whose expression seemed to have been imperfectly chipped out with a dull-edged chisel. There were some marks in it that might have been dimples, if the material had been softer and the instrument finer, but which, as it was, were only dints. The chisel had made three or four of these attempts at embellishment over his nose, but had given them up without an effort to smooth them off. ”

“ The tools used in this operation are very simple. The chisel, or jumper, as it is called, varies in size according to the work to be performed, and its edge is more or less pointed to suit the hardness of the rock to be bored. If the hole is to be small and not deep, it may be bored by a single person; with one hand he manages the chisel, which he turns at every blow so as to cross the previous cut, and with the other hand he strikes it with a hammer of six or eight pounds’ weight, occasionally clearing out the hole by means of a scraper. ”