TOOL STEEL FOR THE UNITED STATES NAVY, 371 



9. Class 3. — Five ^-inch pneumatic chisels will be made from the sample 

 bar. Each chisel will be tested on a nickel-steel plate with a cut ^ inch 

 deep. 



A record will be made of the distance each chisel cuts with a lubricant 

 before it is ruined. 



10. Class 4. — Two |-inch rivet sets will be made from the sample bar. 

 A record will be made of the condition of the sets after a certain number of 

 rivets have been driven. 



11. Modification of tests. — Any or all of the above tests may be modi- 

 fied at the discretion of the engineer officer. 



General. 



12. Method of manufacture. — The tool steels shall be made in either 

 the electric or crucible furnace. The bars must be forged or rolled accurately 

 to the dimensions specified, free from seams, checks, and other physical 

 defects and of homogeneous composition. The tungsten tool steels shall 

 be delivered unannealed, unless otherwise specified, and the carbon tool 

 steels shall be delivered annealed unless otherwise specified. The bars shall 

 be deUvered in commercial lengths and short pieces will not be accepted 

 unless so specified. 



13. Stamps on material. — Kach bar or piece of tool steel, whether 

 sample bar for "selective test," "acceptance test," or material delivered 

 under contract, shall be stamped with the manufacturer's name, his trade 

 name and temper index, and in addition identification stamps of the kind 

 and class of tool steel as given in these specifications. The tungsten tool 

 steel, class i, shall be stamped T-i, and the carbon tool steels, classes 

 I, 2, 3, and 4: C-x, C-2, C-3, and C-4. The letters to be about ^ inch 

 high. If the bars are longer than about 4 feet, the above stamps should 

 be placed at intervals of about 3 feet along the bar. 



14. Acceptance test. — Sample bars for "acceptance test" will be taken 

 from the material delivered under contract to the General Storekeeper, 

 Navy Yard, Philadelphia, Pa., or if the material is inspected at the place of 

 manufacture, the inspector will forward sample bars of the dimensions called 

 for to the General Storekeeper, Navy Yard, Philadelphia, Pa., who will 

 forward them to the engineer officer for him to arrange the tests indicated 

 by these specifications and recommend the acceptance or rejection of the 

 material. If the material proves to be not equivalent to the sample bar 

 furnished with proposal this wiU be considered sufficient cause for rejection. 

 The contractor shall replace the shipment within two weeks, if practicable. 



