Excerpt from High-Speed and Carbon Tool Steels
Previous to 1909, each of the U.S. navy yards prepared requisitions for the purchase of tool steels for its own purposes. These requisitions either specified that proprietary material should be purchased or that the award of contract be based on information obtained by a test of some description on samples submitted by the bidders. By this method, there could be no uniformity in the specifications of the navy yards, and in order to centralize purchasing and to standardize the tool steels, a tool steel board recommended that the Philadelphia Navy Yard be made the purchasing station. This action was taken in 1909 and at that time specifications were drawn up for one high-speed steel and three grades of carbon steel.
The chemical composition required for the high-speed steel differed from that of any of the commercial brands, but the chemical composition of each grade of carbon steel corresponded to that of commercial tool steels. The three grades of carbon tool steel varied principally in their carbon content, in order to adapt them to the purposes for which such tool steels are generally used. The contracts were awarded to the lowest responsible bidder who was able to meet these specifications for tool steel of a chemical composition within the specified limits. The specifications required physical tests in addition to chemical analysis, as a part of the inspection, but these tests did not give decisive results and proved conclusively that it was advisable to revise the existing specifications. This step was taken because these specifications did not provide a means of ascertaining the relative merits of the tool steels offered by the different bidders, or of learning whether there were other tool steels that were superior to those within the specified limits of chemical composition.
In order to overcome these objections, a set of specifications was finally drawn up which are given in a later section of this chapter, as presented by Mr. L. H. Kenney in a paper before the Society of Naval Architects and Marine Engineers. These specifications require the bidders to submit samples of the tool steels which they offer for sale. The samples are manufactured into tools and subjected to physical tests devised to determine the relative merits of the different steels. The data obtained in this way constitute the basis for the award of contracts. In this set of specifications the chemical compositions are given the maximum and minimum limits, the purpose being to indicate to the bidder the kind of tool steel that is wanted, but the physical tests constitute the real basis for the award of contracts.
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