Smithy GN1300 - Manual (Page 120)

Because the feed of successive cuts is toward, not away from the operator, the
thread-cutting set is reversed. Also, you must take lighter cuts because of the cutter's
extension from the toolpost. Take an extra finishing cut without changing the setting of
the compound rest.
Cutting Special-form Internal Threads
You can cut internal forms in all the thread forms used for external threads. There is only
one factor that calls for special attention in cutting special-shaped internal threads: the
difference of clearances between the nut and screw recommended for different thread
types. If you don't have recommended clearances, it is safe to cut a nut (internal thread)
thread 0.005” to 0.010” per inch larger than the screw's outside diameter.
Cutting Threads on a Taper
Cut thread on a taper the same as on a straight shaft, except in the setup of the tools.
set the threading tool at 90° to the axis of the taper, rather than at 90° to its surface.
Granite 1300 Series Operator’s Manual
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