72 FARM MACHINERY 



to heat and draw to an edge by hammering, they recom- 

 mend the following procedure : 



The point should be heated to a low cherry red. If the 

 heat is too intense, the quality of the steel will be injured. 

 Only as much should be heated at once as can be ham- 

 mered. The body of the share must be kept cool and 

 strong so the fitting edges may not be disturbed. After 

 this, the entire cutting edge should be cold hammered. 

 The share should then be set on a level platform, leaving 

 1/16 inch under the middle piece to give proper suction 

 or pitch. The edge must touch all the way along, and 

 the proper bearing must be given at the wing. 



108. Hardening plowshares. A hardened share will 

 retain its cutting edge much longer than a soft share. It 

 is highly advisable, after each time the edge is drawn out 

 by heating and hammering, that the share be hardened. 

 Some soils require hardened steel shares in order that 

 they may retain their scouring qualities. Several reliable 

 manufacturers give directions for sharpening and harden- 

 ing shares made of soft-center steel about as follows : 

 \Sharpening : The whole point should be heated to a very low 

 Ved heat, then the face of the share must be turned down- 

 ward with the heel over the fire and the point about 

 2 inches higher than the heel. In this way the whple 

 length of the share will be heated almost in one heat, 

 as the fire will be drawn along from the heel toward the 

 point. An uneven heat will warp and crack the share. 

 When a moderate heat has been reached it must be re- 

 moved, and it will be noticed if the share is sprung up 

 along the edge. This must be set right, and the following 

 methods may be used to harden : 



First. The edge must be made hard and springy by 

 cold hammering; then the share is to be heated as de- 

 scribed to a low cherry red. It should be let into the 



