CHAPTER XVI 



Sharpening Soft Center 

 Steel Shares 



r*HE majority of steel shares are made of soft center 

 1 steel, a term applied to the use of a layer of low carbon 

 steel between two of high carbon. The soft center steel is 

 by far the most common steel share in use and requires a 

 particular treatment in sharpening because of the peculi- 

 arity of wear upon it. Most of the wear on the share takes 

 place on the underside, hence the lower layer of high 

 carbon steel wears away faster than the upper one. This 

 must be observed very carefully in sharpening the share. 



In heating, care should be taken that only the portion 

 of the share which is to be pounded out is heated. This 

 can be done by laying the share flat with the edge 

 over the center of the fire and filling up the underside 

 with green coals. This keeps the greater part of the 

 share cool, thus preserving its shape. The common 

 mistake is to put the share in the fire in a vertical posi- 

 tion with the edge down. This heats too much of the 

 share and causes it to warp and spring out of shape. 



The pounding should be done from the upper side with 

 the bottom of the share flat on the anvil. This keeps 

 the cutting edge down and works the hard steel of the 

 upper surface over the soft steel in the center, thus pre- 

 serving for the share a hard cutting edge. Since shares 

 receive the most wear on the under side, pounding the 

 share on this side exposes the soft center steel and 

 has a tendency to work the cutting edge out of shape. 



