FLAMES OF ATOMIC HYDROGEN 



145 



The electrodes are ordinarily separated 3 or 4 mm. and the arc assumes 

 a fan shape extending 6 to 10 mm. from the electrodes. Alternating current 

 is generally used. 



Figure 4 illustrates some welds made by the use of this method. At the 

 center is shown a weld between two pieces of 3^ -inch sheet steel (low 

 carbon). The weld is of very high strength and ductility, as is shown by its 

 ability to stand the three mechanical embossing operations to which it was 

 subsequently subjected. 



Fig. 4. — Welds of Low Carbon Steel Made with Atomic Hydrogen Torch. 

 Left — Welded sheet He inch thick, folded twice. 

 Center- — Weld Vs inch thick, tested by embossing. 

 Right — Tube made by welding sheet y?,2 inch thick, subsequently 

 subjected to tests. 



The small sample to the left illustrates a particularly severe test for 

 ductility. The ^/le-inch sheet metal (low carbon steel) after being welded, 

 as in the case just discussed, was folded double along the line of the weld 

 and then folded double a second time at right angles to the first fold. The 

 sample shows a piece cut from the corner of this double fold. The metal 

 shows no signs of cracking. 



The third sample at the right illustrates a cylindrical tube made from 

 low carbon steel sheet metal ^/s2 inch thick. 



After being welded the tube was flattened at its ends in two directions 

 at right angles to each other. The weld showed no signs of failure. 



