All hammers used directly upon hot iron or steel should have the centers of their faces slightly crowning or convex, and the edges well rounded off to prevent their leaving sharp and unsightly marks upon the work, which is very apt to be the case when a hammer with a perfectly level face and sharp edges is used even by experienced workmen.
[Figs. 9,934 and 9,936.-Sledge hammers. Fig. 9,934, ball peen pattern; fig. 9,935, Straight peen pattern.]
The corners between the face and the eye are worked into octagonal shape, and the peen which is circular on the top, stands staright with the handle. The weight of sledge hammers varies according to the size and weight of the work for which they are used; some hammers only weigh 8 lbs, others weigh 20 lbs. or over.
Smaller hammers of the same pattern, weighing less than 8 lbs, are called quarter hammers, and those used for the very lightest work, generally made with a ball peen like a hand harnmer, as shown in fig.9,935, are called backing hammers.
Forge-This consists of an open fire place or hearth arranged for forced draft. The smith heats his metal to the working temperature in the forge. The principal parts of a forge are:
- Fire Pot
- Hearth
- Tuyere
- Blower
- Hood
The small circular type forge, owing to its portability, ran be carried into the field for such purposes as tool dressing and the like.
The best type of portable forge may be taken apart into three pieces by the disconnection of a few wing nuts; fan, pan and legs, packing separately for transportation. Wherever more than rivet heating or chisel dressing is intended, it is advisable to use a large square pan forge, of a more substantial type.
As bellows are undesirable, a forge 28 X 40 ins. may be recommended with a 14 in. fan; the latter will be driven by means of a lever through a sort of sun and planet motion, or by the intervention of a chain like the gear chain
[Fig. 9,942 and 9,943.-Championion cast iron hearth blacksmith's forge. in construction, the hearth is 32 X 45 ins and is supplied with a sloped bottom coal box which is entirely out of the way, as it is beneath the level of the bottom of the hearth, thus keeping the coal in any degree of dampness that the operator desires. The fan blower has spiral gear transmission, each turn of the crank producing 46 revolutions of the fan. Crank turns either way.]
of a bicycle, from a large sprocket wheel. In either case the final multiply- ing power is transmitted to the fan pulley by a belt; as a plain flat leather or textile one.
It is claimed, with a forge of these dimensions, that a welding heat can be obtained on a 3 in. bar in 5 minutes, and on 4 in. iron in 10 minutes. With the addition of a bosh or water tank this forge will weigh about 300 lbs.
Forge Operation.-The fuel used on the forge is bituminous coal. It should contain as little sulphur and earthly matter,
[ Figs. 9,944.-Cutting I. With bottom hardy. Place hardy in hardy hole. Grasp piece to be cut and strike a series,3f blows with the hammer turning piece (if of round section) while hammering ; if piece be flat,hammer first on one side and then on the other. In turning the piece over, be careful that the edge of the hardy is placed directly under the indentation just made on the other side. The piece to be cut should be cold or heated, according to whether the cold cut or hot cut hardy be used. The illustration shows cutting with the cold cut hardy.]
as possible. The best quality coal is called smithing coal, although charcoal or, coke may be used. In building a fire, place a block or brick over the tuyere opening and back the coal in the fire pot, then remove the block or brick and insert shavings in the opening. When the shavings are well ignited place some coke on them and accelerate the fire with the blower. Add a quantity of smithing coal well damped with water and partially burn out the gases.
The depth of the fire should always be liberal, because with a shallow fire the blast will blow through the fire, and the excess air will rapidly oxidize the metal being heated. The fire should be limited to as small a space as is necessary to heat
[ Fig. 9,945.-Cutting 2. With cold or hot cut top hardy (light cutting). Place the piece to be cut on the cutting face of the anvil. Hold Piece with one hand and top hardy with the . other. Place hardy squarely across Piece to he cut and nick or deeply cut by blows delivered by helper with sledges. This operation is performed on the cutting face rather than the hardened face because the former is soft and in case the last blow severs the piece being cut, it would not result in injury to the tool or anvil as would perhaps happen on the hardened face. A good Smith is very careful about marring the hardened face, as good work cannot be done unless this face be in perfect condition.]
the metal. It is regulated by quenching around its exterior portion. Only use the blast when heating the metal, and if it be desired to keep the fire for any length of time it should be well banked.
