Notes from our Sheffield Correspondent.
Page 17
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Local steel manufacturers have the satisfaction of looking back upon the past half-year as one of the busiest on record. The demand from practically all the big motor firms has kept to a consistently-high level, and this seems to indicate brisk business with motor manufacturers, who have also consumed large quantities of tool steel. The outlook is regarded as very bright for the rest of the year. We may, therefore, confidently expect fresh recruits to the ranks of manufacturers who specialize in motor steels. As is only natural, perhaps, steel makers already complain of keen competition, and this has become more pronounced since France became able to supply the major portion of its home requirements, but it is admitted that the expansion of the home trade more than offsets the loss of what was once a valuable market for the productions of some of Sheffield's leading firms.
The demand for all classes of steel specialities has received a remarkable fillip this year, so much so that one manufacturer. who is credited with the intention of producing chrome-vanadium for the motor trade, told me that his works are so full up with orders for other specialities that the matter of chrome-vanadium steel would require more time than they could spare just at the present. and that they must postpone putting the latest development; on the market. While I have referred in my previous notes to the amount of attention which steel makers are devoting to the possibilities of chrome-vanadium—and there is no doubt that it is the most-talked-of alloy at the present time—it must be admitted that very-few manufacturers have actually gone in for it on a commercial scale. Some of the. big concerns affect to believe that the older steels are quite up to all modern requirements, and that such steels have by no means seen their day, no matter for what purpose the engineer requires them. However that may be, there is no gainsaying the fact that most steel makers are busy experimenting with chrome-vanadium alloys, but, as motor manufacturers are averse to paying fancy prices for materials, the question of cost is a veryimportant one.
It is interesting to note that one-of the largest companies — Cammell, T.aird and Co„ Ltd.makes only three classes of steel for the motor trade, and these are nickel-steel, chromenickel, and, what the company is pleased to term, high-tenacity steel. The last-named material has a maximum tensile strength ranging from 53 to 120 tons per square inch, with an elastic limit varying from 40 to 70 tons per square inch, and an elongation varying from a maximum of 23
per cent, to a minimum of 10 per cent. As will generally be agreed, this is a very wide range. This maker's nickelchrome steel has practically the same range, and, with all the three grades of steel mentioned, test pieces of one inch in diameter and nine inches long can be doubled cold without fracture. CammelL Laird and Co. is making nickel-steel in all percentages from three to seven? and from 20 to 35, and is supplying high-tensile steel for back axles and transmission shafts, or any other part which is required to sustain abnormal shocks.
While the above figures will serve as an outline of what up-to-date makers can do with the more-familiar grades of steel, it is interesting to note what is claimed for chrome-vanadium by the local manufacturers. They hold that something fliers is required than high tonsile-strengt h and elongation. Tire steel must possess other qualities, chief amongst which is that of dynamic strength—the resistance to shock and the endurance of fatigue. Makers of chrome-vanadium steel claim that. that material meets the conditions better than the best classes of ordinary steels. However that may be, and no doubt it is a matter upon which experts are bound to differ, at the moment many motor builders are getting along very well with the older grades of steel.. Still, the assertion is seriously being made that motor manufacturers are not yet satisfied that they have a steel which will safely permit of an appreciable reduction in the weight of their finished machines, except it be by sacrificing strength and the power of endurance. Although an important matter to builders of commercial vehicles, it is not nearly so important to them as it is to engineers interested in the newer science—that of aviation. If by the use of chrome-vanadium steel, appreciable reductions in the weight of parts may be made, the material is bound to have a successful future in that growing branch.