FORGING - HARDENING - TEMPERING
and Advice from 1843 by
$14.95 + $2.50
|from: Holtzapffel's Iron & Steel
The conical sockets of socket chisels, garden spuds, and a variety of agricultural implements, are formed out of a bar of flat iron, which is spread out sideways or to an angle, with the pane of the hammer, and then bent within a semi-circular bottom tool also, by the pane of the hammer, to the form of fig. 121; after which they are still more curled up by blows on the edges, and are perfected upon a taper pointed mantdrel, so that the two slightly overlap at the mouth of the socket, and meet pretty uniformly elsewhere, as in fig. 122; and lastly, about an inch at the end is welded.
Sometimes the welding is continued throughout the length, but more commonly only a small quantity at the two ends are thus joined, and the remainder of the edges drawn together with the pane of the hammer.
In making wrought iron hinges, two short slits are cut lengthways nearly through the bar, and towards its extremity; the iron is then folded round a mandrel, set down close in the corner, and the two ends are welded together. To complete the hinge, it only remains to cut out either the central piece or the two external pieces to form the knuckles, (by transverse cuts,) and the addition of the pin or pivot finishes the work.
Musket barrels, when made entirely by hand, were forged in the form of long strips about a yard long and four inches wide, but taper both in length and width, which were bent round a cylindrical mandrel until their edges slightly overlapped; they were then welded at three or four heats, by introducing the mandrel within them instantly on their removal from the fire at the proper heat, to prevent the sides of the tube from being pressed together by the blows of the hammer.
They have been subsequently, and are now almost universally welded by machinery at one heat, whilst of the length of only one foot; on removal from the fire the mandrel is quickly introduced, and they are passed through a pair of grooved rollers: they are afterwards extended to the full length by similar means, but at a lower temperature, so that the iron is not so much injured as when thrice heated to the welding point.
The twisted barrels are made out of long ribbons of iron wound spirally around a mandrel, and welded on their edges by jumping them upon the anvil. The plain stub barrels are made in this manner, from iron manufactured from a bundle of stub nails, welded togethor and drawn out into ribbons, to ensure the possession of a material most thoroughly and intimately worked.
The Damascus barrels are made from a mixture of stub-nails and clippings of steel in given proportions, puddled together, made into a bloom, and subsequently passed through all the stages of the manufacture of iron already explained; to obtain an iron that shall be of unequal quality and hardness, and therefore display different colours and markings when oxidized or browned.
The other twisted barrels are made in the like manner, except that the bars to form the ribbon are twisted whilst red-hot like a rope, some to the right others to the left, and which are sometimes again laminated together for greater diversity; they are subsequently drawn into the ribbons, and wound upon the mandrel, and frequently two or three differently prepared pieces are placed side by side to form the complex and ornamental figures for the barrels of fowling-pieces, described as "stub-twist, wire-twist, Damascus-twist," &c. &c., which are severally and minutely explained and figured by Mr. Greener*.
All these matters are also explained in Mr. Wilkinson's recent and interesting work, which likewise treats of one method amongst others of the formation of the Damascus sword blades; by arranging twenty-five thin bars of iron and mild steel in alternate layers, welding the whole together, drawing it down small, twisting it like a rope, and again welding three such ropes, for the formation of the blade; which exhibits, when finished and acted upon by acids, a, diversified laminated structure, resembling when properly performed an ostrich feather. These blades are now successfully made in England and Germany.
* Greener "On the Gun," 1835; and Greener "On Gunnery," 1841.