62 FARM MECHANICS 



break when being used if tempered too hard. If cold 

 chisels are to be used for cutting iron, the color should 

 be violet ; if the chisels are for cutting stone, purple is 

 the color. Drills for boring iron are tempered a dark 

 straw color at the cutting edge merging back into blue. 

 The water in the dipping tub should be warm, as steel 

 is likely to check or crack when it is tempered in cold 

 water. 



Tool steel should be held in a perpendicular position 

 when it enters the water to cool all sides alike. Other- 

 wise the new tool might warp. It is better to dip 

 slowly, sometimes holding the point, or cutting edge, in 

 the water while permitting the shank to cool slowly 

 enough to remain soft. Some sizes of steel may be 

 tempered too hard at first and the temper immediately 

 drawn by permitting the heat of the shank to follow 

 down almost to the edge, then dip. This is done 

 quickly while watching the colors as they move to- 

 wards the point or edge. 



Draw-filing. Making six-sided and eight-sided 

 punches and scratchawls out of hexagon and octagon 

 tool steel is interesting work. The steel is cut to length 

 by filing a crease all around with a three-cornered file. 

 When it is sufficiently notched, the steel will break 

 straight across. To shape the tool and to draw out the 

 point the steel is heated in the forge to a dull cherry 

 red and hammered carefully to preserve the shape 

 along the taper. Special attention must be given to 

 the numerous corners. A scratchawl or small punch, 

 must be heated many times and hammered quickly be- 

 fore cooling. An old English shop adage reads: 

 ' ( Only one blacksmith ever went to the devil and that 

 was for pounding cold iron." 



After the punch or scratchawl is roughed out on the 



