On my Pultra 1750 all the dials are marked 0 to 100 and the screws are 6mm diameter and 1mm pitch. Possibly 0BA as other threads and screws are BA. I doubt spares are available, but shouldn't be difficult to make a new one.

Andrew

Forgive me asking at this late stage, Dell …

Is it the screw or the nut that you need to make, or both ?

Thread title and text seem at odds with the photos

Incidentally, that nut appears to be engraved D.2,5
… Which I would guess identifies it as being for a 1/4” Diameter screw.

Can’t get at mine at the moment or I would check whether it’s a common feature.

MichaelG.

.

More guessing from me …

I reckon there might just be enough wall thickness there to bore it out and insert a 40tpi bush retained with some Loctite 638 or similar.

MichaelG.

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Edit: __ Taps seem very reasonably priced: 

https://www.tracytools.com/1-4-x-40-tpi-me

Edited By Michael Gilligan on 04/10/2022 19:01:02

Dell, it may be too late but I would advise purchasing the HSS taps rather than the carbon steel, the HSS are made to a better standard IMO. I have had both from Tracytools

I am surprised. If you intend to repair that feed screw nut, why then make a new one?

All the Pultra cross slides i've seen have the feed nuts made in two parts to allow for backlash elimination The grubscrews adjust the distance between the threaded parts, and the main screws lock everythig together. The thick part is approx. 7.5mm deep, the narrow part is approx.  4 mm deep with a 1.5mm boss. 

Dave. 

Edited By david bennett 8 on 06/10/2022 20:56:58

Edited By david bennett 8 on 06/10/2022 21:23:00

I couldn’t use the crosslide

Interesting! From that, I assume that lathe does not have a compound slide?

Dell, mine is metric,but your nut looks rather long. I wonder if yours was made with the intention of being cut into two at a later date. If not , can you see a purpose for the grub screw holes?

dave.