Quote Originally Posted by lakeside53
One small thing many don't realize is that if you cut threads that are a "multiple" of the lead-screw pitch, you don't need a dial indicator - the half nuts can be engaged anywhere they will lock onto the lead screw. i.e. 8 tpi lead-screw - I can cut 8, 16, 24, 32, 40, 48, 56.... tpi. I haven't checked, but intuitively the same should hold for metric.

A very common metric lead screw is 3mm pitch such as on my generic Chinese 12x36 lathe. If I am reading the tables correctly thread pitches of 0.5, 0.6, 0.75, 1.0, 1.5 and 3.0 can be cut without reference to the treading indicator. Other thread pitches are awkward requiring selection of the correct pinion for the threading indicator. Supplied pinions are 14, 15 and 16 tooth. There are 8 points marked on the indicator.

I have tried using the indicator but never perservered.