The draw knife should be forged from a
better grade of steel than our regular cast steel grade;
however, very good results can be obtained from such grade if a
little care is used in the finish hammering of the blade. If the
blade is carefully worked it will hold a very good cutting edge.
The drawings show the method of forging a six inch
blade draw knife. If an eight inch blade is wanted, simply add the
two inches and forge the handles as shown.
The stock shown is one-fourth inch thick, one inch
wide and eleven and .one-half inches long. Start from the center of
the stock and measure off the length of the blade, center punch and
fuller as shown in Fig. 1.
Now draw out the handles to size and note that they
run one1'ourth by one-half for two inches before the taper starts. The taper starts at the point where the bend will be made later.
Leave the handles straight at present.
Now place the groove in the blade as shown in Fig. 2
with a fourth inch top fuller.
This is the most difficult part of the work, as the
groove must neither be too high nor too low, and at the same time it
must be straight. If each handle has been carefully forged to
one-half inch wide, little difficulty will be experienced.
Start the
fuller at each end first then work to the center. Notice that the
groove comes up in the handle a little and leave the back of the
blade seven-sixteenth inch wide. The groove should be one-eighth
inch deep, leaving the blade one-eighth inch thick.
The blade is now drawn out with a set hammer to the
thickness required. This will cause the blade to curve backward
which makes it necessary to straighten the back often.
When
finished, the blade has a little curve but it is bettor to have the
blade straight until after the draw knife is ground and polished.
The forging will leave the ends of the blade a little uneven, which
should now be squared with a file, leaving the corner next to the
handle round. The work should now be placed on a medium emery wheel
and the rough hammer marks removed, after which it can be buffed on
the 60 wheel.
Now see that the handles are the same size and length, and after
marking the two inches for the bend with a center punch, bend the
handles to the angle shown in Fig. 4.
