TOOL STEEL FOR T'HE UNITED STATES NAVY. 359 



Copies of the above specifications can be obtained upon application 

 to the various navy pay officers or to the Bureau of SuppUes and Accounts, 

 Navy Department, Washington, D. C. 



References: Department's order, dated December 12, 1908; S. and A. 

 73975. 



SPECIFICATIONS FOR CARBON TOOL STEEL. 



Grade "A." 



Tool steel of this grade is to be used for the following purposes: — 

 Finishing tools, special machine cutting tools, etc. Grade "A" tool steel 

 shall have a chemical composition approximately as follows: — 



Per cent. Per cent. 



Carbon i.io to 1.25 



Silicon 20 to .30 



Manganese 20 to .30 



Phosphorus, not more than 015 



Sulphur, not more than 015 



Tungsten, as desired, but not to exceed 3.00 



Vanadium, as desired. 



Physical Tests. — Samples submitted shall be made up into a standard 

 I by 1 1 inch round nose roughing tool, and with a depth of cut of ^V inch, 

 tV inch feed, shall cut at the rate of 15 feet per minute for 20 minutes with- 

 out serious injury to the nose of the tool. After redressing and grinding, the 

 cutting speed shall be increased to 30 feet per minute, the depth of cut 

 reduced to | inch and feed to ^ inch. The tool shall stand up 20 minutes 

 under this cut. The above test should be carried on a steel cylindrical 

 forging of the same physical character as called for under the high-speed 

 tool steel test above. 



Grade "B." 



For taps, milling cutters, drills, forming tools, threading tools, threading 

 dies, punches, etc. 



Grade "B" tool steel shall have a chemical composition approximately 

 as follows : — 



