Iron rod

“ So important is the relation between cast iron, wrought iron, and steel that it may be well to illustrate this by the use of a diagram due to Professor Merriman. Assume that short rods of these materials, each of the same length and one square inch in cross section, are subjected to great stretching force by the use of a testing machine. As this force increases up to the elastic limit of six thousand pounds, the cast-iron rod becomes elongated proportionally. It breaks suddenly when the stress reaches twenty thousand pounds. ”

“ Pieces of iron in the presence of a loadstone (even if they are not * touching the loadstone) run together, seek one another anxiously and embrace one another, and when joined are as if they were cemented. Iron * filings or the same reduced to powder inserted in paper tubes, placed upon a stone meridionally or merely brought rather close to it, coalesce into one body, and so many parts suddenly are concreted * and combine; and the whole company of corpuscles thus conspiring together affects another piece of iron and attracts it, as if it constituted one integral rod of iron ”

“ The selection of this filling rod, or wire, is all-important, for the skilful and successful iron worker uses a piece of metal that will fuse well with the parts to be repaired, at about the same temperature at which they themselves will fuse. Mild steel or Norway iron which is 90 per cent. pure is frequently used, but there are no hard and fast rules because every master mechanic has his own ideas about such 258 things, and would not take the word of any manufacturing company. ”

“ He advocates the use of iron as the best metal to use, specifying a weight of 2 lbs. per foot. He thinks wire ropes are more easily applied than rods, ribbons, or tubes, and prefers a rope 1·2 in. diam. of six strands of seven No. 11 B.W.G. wire, each round a hemp core—costing about 5d. per foot. Conductors should be specified in terms of electrical units, viz.: ·3 ohms per 1000 yards, and be continuous. Every unavoidable joint should be soldered. He has found in practice many bad joints, especially in copper conductors. ”

“ The point ought to consist of a solid copper cylinder, 3⁄4 inch diameter, 6 inches high, conically pointed, the top angle being about 30 degrees, and with gilt top. At the lower end a nut is applied, by which the point is screwed and afterwards soldered to the end of the rod. Most conveniently the rod is formed of round iron, which, like the rest of the conductor above earth, if constructed of iron, is painted over or galvanized. Under earth only galvanized iron is suitable. The upper diameter of the rod is 3⁄4 inch ”

“ Bolting the parts with iron rods, or holding them together by means of chains, is the usual and commonly the better method. The iron is not to go around a limb, however, for girdling results; the rods or chains should be secured by bolts bored through the wood and pulling against large heads or washers. ”

“ It is so highly 75refined that it can hardly be called steel at all but is often called “open-hearth iron” or “ingot iron.” It is probably the purest iron on the market in commercial quantities to-day. While in the chemical laboratory iron of considerably greater purity can be made, for a commercial product this is remarkably pure, seldom containing more than 1⁄4 per cent of elements other than the metal, iron. ”

“ It has the immense advantage of disposing the metal so that its fibres encircle the piece, thus applying the strength of the iron in the most effective way. The bars from which the coils are prepared are made from “scrap” iron, such as old nails, horse-shoes, &c. A pile of such fragments, built up on a wooden framework, is placed in a furnace and intensely heated. When withdrawn the scraps have by semi-fusion become coherent, and under the steam hammer are soon welded into a compact mass of wrought iron, roughly shaped as a square prism. ”

“ It is remarkable, also, that we are enabled to superpose and obtain the maximum effects on thin strips of iron from 1⁄4 to 1⁄2 millimeter in thickness, while in thicker rods we have far less effect, being masked by the comparatively neutral state of the interior, the exterior molecules then reaching upon those of the interior, allowing them to complete in the interior their circle of attractions. ”

“ Some kinds are broken up to be used as foundation for roads; others are granulated by being run into water, and so made into cement. Over in Germany, where the ores are rich in phosphorus, they grind up the linings of the furnace to make phosphatic fertilizers for the farmers.”
“Then,” said Dr. Crandon, “the making of iron involves the use of chemistry, doesn’t it?”
“It certainly does,” answered Mr. Prescott; “from the chemical composition of ores to the finished product. We are learning a great deal just now from the chemists about steel alloys. ”

“ A quantity of molten iron should be kept in the cupola or in a large ladle, so as to give the different brands of iron a chance to mix. In most all the foundries at Wheeling, West Virginia, the cupolas are never stopped from the time the blast is put on until the bottom is dropped. A large ladle is set on trestles in front of the cupola, in such a manner that the iron can run into it from the cupola and be poured out into the smaller ladles at the same time. The iron is all run out of the cupola as fast as it is melted, and is mixed in a large ladle. I think this is a good way of mixing iron. ”

“ The strength of iron is at its maximum in the smallest mechanical structures.
2. The quality of the metal is improved as it is subjected to greater pressure and condensation.
The extent to which this improvement may be carried has never yet been ascertained; every fresh manipulation improves its quality. The tenacity of wrought iron is best displayed in a wire, drawn out until it is not thicker than a human hair. Large masses of wrought iron are weak and spongy in geometrical progression with the mass, and the crystalline or molecular form increases with the mass. ”

“ During the melting of the charge the heat is kept as high as possible and the molten iron is “puddled,” i. e., stirred, by the “puddler” or his helper with a “rabbler” or iron bar. In order to take out the phosphorus and sulphur, which for best results should be removed before the carbon is eliminated, the heat of the furnace is lowered somewhat as soon as all of the pig has melted, and some iron oxide is mixed into the “bath” of molten iron and cinder. Most of the phosphorus and sulphur are chemically acted upon and pass into the cinder which covers the iron. ”

“ Crandon.
“Now,” said Mr. Prescott, “we’ll start for some more giants. Coming, Farnsworth?”
“Sorry, not to-day. Call again!”
“The steel mill comes next on my program,” said Mr. Prescott, when they went out. “I want you to see a Bessemer converter, an open hearth, and some crucibles, because that practically covers the different methods of making iron and steel.
“Here is the Bessemer converter. You see it is an iron cylinder made of wrought iron plates, and it tapers off at the top in a conical end. See. It is swinging down to be filled almost as easily as you can turn your hand over. ”

“ Prescott. “Heat expands iron. If we didn’t keep it cool, the screw wouldn’t be the right size when it is done.
“Cold naturally works the other way. Ever hear about the iron bridge where the parts wouldn’t quite come together, so they put ice on to do the job?” he asked, but he kept right on, without waiting for Billy to answer.
Billy saw other machines boring holes and rounding corners. It seemed as if iron could cut iron into any shape that anybody wanted. ”

“ Thus, when combined with carbon, in varying proportions, substances are produced, so different, but each so valuable, that they might almost be regarded in the light of distinct metals,—such, for example, as cast-iron, and cast and bar steel; the various qualities of iron enabling it to be used for purposes so opposite as a steel pen and a railroad, the needle of a mariner's compass and an Armstrong gun, a surgeon's lancet and a steam engine, the mainspring of a watch and an iron ship, a pair of scissors and a Nasmyth hammer, a lady's earrings and a tubular bridge. ”

“ Again, iron which has been excited by a loadstone, * if that iron on account of obstacles should not be able to turn round immediately in accordance with its nature, as happens with a versorium, is laid hold of, when a loadstone approaches, on either side or at either end. Because, just as it can implant, so it can suddenly change the polarity and turn about the formal energies to any part whatever. So variously can iron be transformed when its form is adventitious and has not yet been long resident in the metal. ”

“ Billy looked at him questioningly.
“That was rather technical, wasn’t it, Billy? You see, I was talking to a technical man. Just between you and me, meteoric iron comes down from the sky, from what we call shooting stars. Sometimes large pieces are found. I suppose that much of it falls into the sea. It is the purest iron that has ever been found.”
“What about magnetic iron?” asked Dr. Crandon. “Where does that come from?”
“At the present time,” answered Mr. Prescott, “most of it comes from Sweden and Norway. It makes the best kind of steel. ”

“ The manufacture of wrought iron, by means of bituminous coal, is executed at three successive processes, and is facilitated by very great improvements in the machinery. Where hammers are still used, they are much increased in weight, and [Pg 374] driven with greater velocity; but by far the greater part of the operation of drawing the bars is effected by means of rollers. The plan of these is in some measure borrowed from the slitting mill, in which bar iron is reduced into rods and thin rolls for various uses. ”

“ But since modern methods of manufacturing have been adopted, tons of metal, which would have been classed as iron if judged by the cooling test, are at present known as mild or soft steel.
Steel may properly be defined as an alloy of iron with carbon, the latter not exceeding 1.8 per cent; the materials are completely fused and poured into molds, allowed to cool, and then rolled into shape. In the processes of making wrought iron the materials are only partly fused and are not cast into molds, but are taken out of the furnace in a soft, pasty condition suitable for immediate working. ”

“ Ordinary cast iron, while strong and hard enough for many purposes, still is brittle by reason of the large proportion of carbon and other impurities which it contains. These impurities may be burned out in the puddling process, and the nearly pure iron thus obtained, called malleable or wrought iron, has a toughness enabling it to resist far greater strains than cast iron can stand. Intermediate between the two irons, and containing one per cent of carbon, more or less, is still another product, steel, which may be made even more tenacious than wrought iron, or even harder than cast iron. ”

“ While I write, iron is doubtless flowing from blast furnaces in England, Wales, and Scotland; while I write, ingots of white-hot Bessemer steel are being dealt with under the steam-hammer or in the rolling-mills; while I write, horse-shoes are being forged, and, at each moment, in one way or another, pieces of iron of every temperature could be found, from those which are as cold as the iron apparatus used by Sir James Dewar in his experiments in the liquefaction of air, up to the glittering melted steel which is poured from the tilted converter. ”

“ It was only after the next great advance that we found man utilizing iron for his purposes of civilization. This metal, which with us is so common, was in those days very expensive, so much so that it could be used only for purposes of war and as the gifts of kings.
But the world was traveling fast and it was not long before the iron-carbon alloy, steel, was produced. Even so, many hundreds of years elapsed before the present wonderful age was ushered in through the great inventions of Henry Bessemer and the Siemens brothers. ”

“ It is probable that, in several well-authenticated instances in which this really did happen, the joints were eaten away by oxidation, as in the case of the chains; still, the effect of such occurrences was all the same. The joining of strips of lead together was a far easier task than that of handling iron in the same way, particularly for inexperienced workmen, and thus the employment of the metal continued for some time. ”

“ Manufactured irons differ very greatly amongst themselves. For one kind is tenacious in its nature, and this is the best; one is of medium quality: another is brittle, and this is the worst. Sometimes the iron, by reason of the excellency of the ore, is wrought into steel, as to-day in Noricum. From the finest iron, too, well wrought and purged from all dross, or by being plunged in water after heating, there issues what the Greeks call στόμωμα; the Latins acies; others aciarium, such as was at times called Syrian, Parthian, Noric, Comese, Spanish ”

“ The rod of iron with which he rules her never appears in company—it is a private rod, and is always kept upstairs. ”

“ Thus, for instance, experience has demonstrated that piston-rings of cast iron will wear smoother, better, and equally as long as those of steel, and longer than those of either wrought iron or brass, whether the cylinder in which it works be composed of brass, steel, wrought iron, or cast iron—the latter being the more noteworthy, since two surfaces of the same metal do not, as a rule, wear or work well together. So also slide-valves of brass are not found to wear so long or so smoothly as those of cast iron, let the metal of which the seating is composed be whatever it may ”

“ Pure iron is never obtained commercially, the metal always being mixed with various proportions of carbon, silicon, sulphur, phosphorus, and other elements, making it more or less suitable for different purposes. Iron is magnetic to the extent that it is attracted by magnets, but it does not retain magnetism itself, as does steel. Iron forms, with other elements, many important combinations, such as its alloys, oxides, and sulphates. ”