nearly half way through the depth. The part b₁ is then removed either by cutting with a hot saw along the dotted line, or by means of a special cutting tool, and then the remaining portion c (Fig. 11b) is roughly rounded in swage blocks
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Fig. 11.—Stages in Forging a Crank Axle.
under the steam hammer. The portion d is also removed by means of special cutting tools, and the middle part e between the cranks is roughly swaged down to a circular form. To cut out the portion b₂ the forging is re-heated and the porter bar p is re-welded to the opposite end. After this operation is complete, the appearance of the axle is as in Fig. 11b.
As the two cranks have to be at right angles to each other, one of the two parts f₁f₂ has to be twisted through 90°. This is done by firmly holding the crank f₁ supposing this to be the one to remain in its original position, between the
