The Lloyd oxy-acetylene is the latest method of producing thin gauge steel tubing. Until this method was invented thin-gauge tubing was exceedingly costly in comparison to larger gauge tubing, owing to the many more treat ments requited in order to get a thin-walled tube. The Lloyd oxy-acetylenc method re quires steel ribbons of desired widths. The ribbons are passed through oval-shaped rollers, thus bringing the square edges close together. The partially shaped tubing then passes to other rollers which press the edges very dose to gether. At this point oxy-acetylene heat is ap plied at about 2,500° and the welding takes place. It is then polished, cut off to desired lengths and comes out of the machine ready for use. A single machine accomplishes the entire work. The Lloyd oxy-acetylene method differs from the butt welding in that the steel edges are not pressed together and only a very small portion of the partially shaped tubing is heated. So delicate is the operation that a seamless tube is produced in desired lengths without waste.
History.— While the use of iron and steel has become so common in mechanical and structural work as a result of modern ingenu ity, it is hard to realize that nearly five and one-half centuries passed by after the dis covery of iron before steel became a commer cial product. Iron was first found, say his torians, in the pyramid of Gizeh, where it had been placed by builders, most likely as a relic. This same iron to-day rests in the British Museum. So far as is known iron was used commercially for the first time by Assyrians in Egypt. They made various kinds of tools, etc. History shows that for some time before the coming of Christ iron was used in making the implements of war, tools and other articles. It was not until 1350, however, that cast iron and steel first made their appearance, when a German metallurgist produced them. The in ventions of the Bessemer process for manu facturing steel opened this metal up to com mercial use. This took place in 1855. The use of steel became an important product in mechanical and manufacturing history very soon after processes for preparing it were in vented. The first known use of steel as a tube or pipe is the Coolgardie pipe-line, 328 miles long and 30 inches in diameter. This pipe was not welded. It was formed by taking ribbon
steel and bending into semi-circular shape. The edges were inserted into steel bars with grooves on either side. Heavy •pressure was applied on the plates and bars, thus rendering the pipe serviceable. Steel tubing itself was one of the very latest uses of steel owing to the early inability to make welded steel tubing so that the welded portion was of the same strength as the rest of the tube. Later, just the op posite condition arose, but to-day the piercing and Lloyd oxyacetylene methods have over come all these objections. The early lap and butt welding methods were not satisfactory for high-class work, and it was not until Mannes man Brothers, German by birth, but residents of Landore, Wales, and backed by British financiers, brought out the piercing method. They took round or square steel billets and pierced and rolled them to the size desired. This was a seamless method in which no weld ing was required and, therefore, gave great impetus to steel tubing uses. Improvements on the Mannesman method have been made 'by W. C. McCool of Beaver Falls, Pa., he being the first to invent a cold draw bench for draw ing cold shafting. R. C. Steifel made other improvements at Ellwood City, Pa. He fol lowed these with new improvements at Shelby, Pa., while George J. Thust added more at Detroit and Milwaukee, where mills were built in which the piercing method was used. The great difficulty of the piercing method arose when thin-gauge tubing was required, for the thinner thegauge the more rolling and drawing required. These many operations made the cost of thin-gauge tubing almost prohibitive. It was not until 1910 that Marshall B. Lloyd of Menominee, Mich., solved the problem of the thin-gauge, seamless steel tubing. High prices, long delays and imperfect thin-gauge tubing drove Mr. Lloyd into inventing the Lloyd oxyacetylene method of making seam less steel tubing. By this method the very thinnest gauge steel tubing is possible, the thin ner the tubing the cheaper the price, due to the fact that under the Lloyd method the real cost of the tubing is the material, while in all other cases the high cost is due to the numerous operations in which labor plays an important part along with material.