PROPERTIES OF STRUCTURAL METALS. 45 



MANUFACTURERS' STANDARD SPECIFICATIONS. 



STRUCTURAL STEEL. 



1. Process of Manufacture. Steel may be made by either the open- 

 hearth or Bessemer process. 



2. Testing. All tests and inspections shall be made at place of 

 manufacture prior to shipments. 



3. Test-pieces. The tensile strength, limit of elasticity, and ductility, 

 shall be determined from a standard test-piece cut from the finished ma- 

 terial. The standard shape of the test-piece for sheared plates shall be 

 as shown by the following sketch : 



"W- ----- -Parallel-section-not-less-than-^ ---- -M 



ttJit 



. Piece to be of same thickness as Plate 

 A-bout-18 *J 



On tests cut from other material the test-piece may be either the same 

 as for plates, or it may be planed or turned parallel throughout its entire 

 length. 



The elongation shall be measured on an original length of 8 ins., 

 except when the thickness of the finished material is T ^ in. or less, in 

 which case the elongation shall be measured in a length equal to 

 sixteen times the thickness; and, except in rounds of in. or less in 

 diameter, in which case the elongation shall be measured in a length 

 equal to eight times the diameter of section tested. Two test-piece 

 shall be taken from each melt or blow of finished material, one for ten- 

 sion and one for bending. 



4. Annealed Test-pieces. Material which is to be used without anneal- 

 ing or further treatment is to be tested in the condition in which it 

 comes from the rolls. When material is to be annealed or otherwise 

 treated before use, the specimen representing such material is to be 

 similarly treated before testing. 



5. Marking. Every finished piece of steel shall be stamped with the 

 blow- or melt-number, and steel for pins shall have the blow- or melt- 

 number stamped upon the ends. Rivet and lacing steel, and small 

 pieces for pin-plates and stiffeners, may be shipped in bundles securely 

 wired together, with the blow- or melt-number on a metal tag attached. 



6. Finish. Finished bars must be free from injurious seams, flaws, 

 or cracks, and have a workmanlike finish. 



