Handtap No. 1 with pilot guide, to assure
the concentric start at manual threading.
Tapping only 3-4 threads is enough.
3 thread chamfer lead.
Rake angle 1°÷3°.
A648/2
Handtap No. 2 with the same thread
sizes as A648/1.
3 thread chamfer lead.
Rake angle 1°÷3°.
A648/3
Handtap No. 3 that finishes the thread to
the required tolerance.
Not suitable to use as single pass tap.
3 thread chamfer lead.
Rake angle 1°÷3°.
A648
Handtap set consisting of 3 taps:
A648 = A648/1 + A648/2 + A648/3.
You must tap continuously, it means
without stop and reversing the tap to
break the chip.
High alloyed steels
