STELLITE, name applied to a series of alloys consisting essentially of cobalt and chromium. The alloy consisting of cobalt and chromium only is made by melting the two metals together and casting the resulting mix ture into bars. If the chromium does not ex ceed 25 or 30 per cent, these bars may be forged into rods or rolled into sheets. During the cast ing and rolling process the alloy becomes cov ered with a thin film of oxide of a dark blue-black color. When this is ground off, however, and the rod or plate is polished, it shows a beautiful lustre which is not dimmed by exposure to any kind of metal conditions. It remains perfectly bright in moist air, and even in the atmosphere of a chemical labora tory. In fact it retains its lustre under all cir cumstances and is only equaled in this respect by gold and the metal's of the platinum group. It may be readily forged into spoons, knives, forks, etc., and these articles are so hard that they can scarcely be scratched by the file. The alloy is stiffer than steel. In fact it is the most rigid alloy in use and, while its elastic limit is not very high, it is sufficient for practical pur poses in almost any form into which it may be made. When a certain amount of tungsten or molybdenum is added to the alloy, the hardness is greatly increased, and some of the alloys thus formed are harder than any steel ever pro duced. These latter are termed tool metal
alloys, and when cast into bars need only to be ground to a cutting edge and placed in the tool holder of the lathe to render them immediately available. Results obtained with these tools in the machine-shop are very remarkable. Red hot shavings may be cut from steel bars without injury to the edge of the tool, and on certain kinds of work a machinist is able to turn out from 25 to 100 per cent more work in a day than with the best high-speed steel tools. The name stellite is derived from the Latin word Stella, meaning a star, because when once polished it always retains its lustre or brightness. Stellite alloys have been manufactured into pocket and table cutlery, spoons, forks, mirrors, razors, knife edges for bakances, surgical tools, dental instruments and machine tools. Pocket knife blades made of this metal retain their lustre under all circumstances, and may be used for cutting apples, oranges, lemons and various other fruits without marring their lustre in the slightest degree.