b) Through-feed method (Figure 6.4)
Here, the rolling dies have grooves with
no pitch; the groove cross section is that
of the standard flank profile. The thread
pitch is produced by skewing the die axes
by the pitch angle of the thread. By this
means the workpiece is given an axial
thrust and moves one pitch length in axial
direction for every full revolution. As the
axial thrust kicks in immediately when
the workpiece enters the assembly, larger
threads are not formed to full depth in
one pass.