SHOP TESTS. 



279 



comparison to metals by different makers, each authority 

 having its own particular requirements. In these tests 

 no load is measured, as they are simply for the purpose 

 of ascertaining the ductility and endurance. 



As illustrating what kind of requirements are specified, 

 it may be stated that the rules laid down by the British 

 Admiralty are as follow : Test for 



Steel Plates. " Strips cut lengthwise of the plate, l^in. 

 wide, heated uniformly to a low cherry red, and cooled in 

 water at 82 Fah., must stand bending in a press to a 

 curve of which the inner radius is one and a half times 

 the thickness of the plated tested." This heating and 



FIG. 142. 



BEST WROUGHT IRON AND MILD 

 STEEL, BENT CLOSE. 



FIG. 144. 



NICKING AND COLD BENDING 

 TEST. 



quenching is to discover if there is any tendency to 

 harden. 



Lloyd's rule also says: " Strips cut from plate, angle, 

 or bulb steel to be heated to a low cherry red, and cooled 

 in water of 82 Fah., must stand bending double round 

 a curve of which the diameter is not more than three 

 times the thickness of the plates tested." See Fig. 139. 

 The Board of Trade requirements are the same. 



Iron Plates. For iron plates the Admiralty test is 

 as follows : Hot, to be bent from 90 to 125, without 

 fracture, as in Fig. 140 : in this figure and the next one 



