370 



TOOL STEEL FOR THE UNITED STATES NAVY. 



Carbon tool steel. 



Carbon 



Chromium. 

 Manganese . 

 Phosphorus 



Silicon 



Sulphur 



Vanadiiun . 

 Iron 



Class I, 

 per cent limit. 



Maxi- 

 mum. 



1.25 



t 



•35 

 .015 

 .40 

 .02 



t 



Mini- 

 mum. 



1. 15 

 t 

 ■5 

 .00 

 .10 

 .00 

 t 



Class 2, 

 per cent limit. 



Maxi- 

 mum. 



1. 15 



t 



•35 

 .015 

 .40 

 .02 



t 



Mini- 

 mum. 



1.05 



t 



•15 

 .00 

 . 10 

 .00 



t 



Class 3, 

 per cent limit. 



Maxi- 

 mum. 



0.95 

 t 



•35 

 .02 

 .40 

 .02 



Mini- 

 mum. 



Class 4, 

 per cent limit. 



Maxi- 

 mum. 



0.85 



t 



•15 

 .00 

 .10 

 .00 



t 



0.85 



t 



•35 

 .02 

 .40 

 .025 



t 



Mini- 

 mum. 



0.75 



t 



• 15 

 .00 

 .10 

 .00 



t 



*Remainder. 



tOptional. 



PHYSICAL TESTS. 



Tungsten Tool Steel. 



6. Class I. — The sample bar will be forged into 5 tools, treated and 

 ground to the No. 30 form of the Sellers system of lathe tool forms. Each 

 tool will be tested on a nickel-steel forging of about 100,000 pounds tensile 

 strength, with a cut J inch deep, i^ inch feed, and a cutting speed of 50 

 feet per minute. Each tool will be twice reground and retested. A record 

 will be made of the length of time each tool cuts without a lubricant or 

 cutting compound before it is ruined. 



Carbon Tool Steel. 



7. Class I. — Five ^-inch diameter, 4- tooth facing mills will be made 

 from the sample bar and tested on a piece of f-inch ship's plate without 

 lubricant. Each mill will be run until it is so dull that it breaks either in 

 the teeth or in the shank. The depth of cut will be 0.08 inch, the revolu- 

 tions per minute of the mill wiU be 370, and the feed of material 20 inches 

 per minute. A record will be made of the length of time each mill operates. 



8. Class 2. — Five ^-inch diameter, 4- tooth facing mills will be made 

 from the sample bar and tested on a piece of |-inch ship's plate without 

 lubricant. Each mill will be run until it is so dull that it breaks either in 

 the teeth or in the shank. The depth of cut will be 0.08 inch, the revolu- 

 tions per minute of the mill will be 370, and the feed of material 20 inches 

 per minute. A record will be made of the length of time each mill operates. 



