The rolling of high-speed steel is an art known to very few. The various factors governing the proper rolling are so numerous that it is necessary for each individual rolling mill to work out a practice that gives the best results upon the particular analysis of steel it makes. Important elements entering into the rolling are the heating and finishing temperatures, draft, and speed of the mill. In all of these the element of time must be considered. High-speed steel should be delivered from the rolling mill to the annealing department free from scale, for scale promotes the formation of a decarbonized surface. In preparation of bars for annealing, they are packed in tubes with a mixture of charcoal, lime, and other material. The tubes are sealed and placed in the annealing furnace and the temperature is gradually raised to about 1,650 deg.F., and held there for a sufficient length of time, depending upon the size of the bars. After very slow cooling the bars are removed from the tubes. They should then show a Brinnell number of between 235 and 275. The inspection department ranks with the chemical and metallurgical departments in safeguarding the quality of the product. It inspects all finished material from the standpoint of surface defects, hardness, size and fracture. It rejects such steel as is judged not to meet the manufacturer's standard. The inspection and metallurgical departments work hand in hand, and if any department is not functioning properly it will soon become evident to the inspectors, enabling the management to remedy the trouble. The successful manufacture of high-speed steel can only be obtained by those companies who have become specialists. The art and skill necessary in the successful working of such steel can be attained only by a man of natural ability in his chosen trade, and trained under the supervision of experts. To become an expert operator in any department of its manufacture, it is necessary that the operator work almost exclusively in the production of such steel. As to the heat treatment, it is customary for the manufacturer to recommend to the user a procedure that will give to his steel a high degree of cutting efficiency. The recommendations of the manufacturer should be conservative, embracing fairly wide limits, as the tendency of the user is to adhere very closely to the manufacturer's recommendations. Unless one of the manufacturer's expert service men has made a detailed study of the customer's problem, the manufacturer is not justified in laying down set rules, for if the customer does a little experimenting he can probably modify the practice so as to produce results that are particularly well adapted to his line of work.