356 TOOL STEEL FOR THE UNITED STATES NAVY. 



Card No. 6, B 3, from tool No. 1-3, which was re-treated after the selec- 

 tive test had been completed. The top of this tool was ground off and 

 polished for etching. The photomicrographs were made to determine the 

 differences in the structure of the tool steels. 



When this navy yard was selected as the purchasing station for tool 

 steels, there was no information on file as to the dimensions or amounts of the 

 several kinds of tool steels which would be needed by the navy yards per 

 annum. Tool steels were, therefore, purchased under the specifications 

 given in Appendix A from time to time as required. This method necessi- 

 tated advertising for bids at intervals and caused delays in delivering to a 

 navy yard the tool steel it had ordered. 



The expense of a selective test as given in Appendices C and D would 

 be prohibitive if it were to be made to determine the award of contract for 

 small quantities of tool steel. It was therefore decided to recommend the 

 purchase of a six-months supply of tool steels in order, to test the specifica- 

 tions given in Appendix C, to reduce to a minimum the ratio of the cost of 

 the selective test to that of the entire amount of tool steel purchased, and to 

 get a stock in store. Schedule 3893 was prepared for this purpose. 



The selective test under Schedule 3893 indicated that only minor modi- 

 fications of the specifications were necessary; and it was therefore considered 

 safe to recommend that an annual contract for tool steels be made. The 

 contract should be so framed that tool steels of any reasonable dimensions 

 and in accordance with the classification of the specifications given in Appen- 

 dix D, could be ordered in any desired quantities throughout a fiscal year. 

 Schedule 4469 was prepared to meet these requirements, and an extract, 

 which is given in Appendix E, has been made from it to explain the general 

 scheme. 



The writer wishes to acknowledge the kind assistance of Mr. Victor 

 Johnson, of the Machinery Division, Philadelphia Navy Yard, and of the 

 representatives of the tool steel manufacturers who observed the forging, 

 treating and testing of the tools during the selective test of tungsten tool 

 steel, class i, Schedule 4469. 



