I am restoring a 75 + yo Myford ML 4. There is 75 thou backlash in the cross slide which is in the cast iron thread not in the turn wheel gap. This model does not have a bronze nut! I want to make a couple of bronze nuts but cannot locate a 5/16in x 12 TPI ACME tap, or preferably a 3 part set. Tracy tools will make one for £200 + Vat, more than lathe is worth probably. Any help for a beginner appreciated. I note that most messaging is for ML7's which I believe have 3/8in lead screws and taps are available.

Thanks for feed back Old Mart. I have considered this, going for a 3/8in leadscrew in saddle slide and cross slide definitely opens up tools readily available. Have to check that tapping the castings 3/8 ACME allows sufficient thread cover, the tapped through hole is very close to the tool post mounting plane. The ML4 is clearly a much lighter item than 7 series, guess Myford had learnt lessons during WW2 period.