Clarke metal worker lathe toolpost stud size

Hi brand new here. I have the above lathe and have just inboxed a quick change toolpost. Thankfully the issue of tools never sitting quite centre will now be sorted but as the toolpost is taller than the original one the stud to tighten it down is now too short. I shall make a new handle that will sit further in the toolpost with a shoulder on it but I have no idea what size the thread is. It looked to me to be around 10mm but I have tried an m10x1.5 and m10x1.25 and whilst these seem about the right size they do not turn any further than a couple of mm. So I believe it to be an imperial size. Have you any suggestions on what sizes this could be?

Many thanks.

Matt

This is a Sieg lathe made in China, the tool post stud is definitely not imperial. I have a similar machine and when I put a QCTP on mine it came with a suitable sized stud to replace the original, and works fine. I would check the thread in the topslide for damage and if necessary run a tap through. Of course if you bought the lathe secondhand a previous owner might have done something weird.

Regards

Martin

Edited By Martin Shaw 1 on 02/02/2018 21:44:22

My SIEG C2 has a standard M10 thread. So that's 1.5 mm pitch.

Hi Matt it is possible the stud has stretched giving you a false pitch check the hole with a known thread.

David

Thanks for the replies here, I’ve just seen them. I ran a number of taps and dies in both threads, and although needing a clean up they appear to be an m10x1.5. Not the best condition it would seem. Thanks for the assistance I didn’t want to run a die down it before being sure what the thread was. Seems tomorrow’s job is making a new handle for the toolpost. I got the lathe brand new about 6 years ago so it’s is likely just wear and tear on it it does get used a lot.

Easy to overtighten - a greased washer (some folks use a thrust bearing) on top of the toolpost can help, but its thickness will affect where the 'tight' position is.

Neil

The greased washer sounds like a good trick. Best to make it 1.5 mm thick if the tight position is critical. I'll try one before ordering a roller bearing which I planned to do.

Might be worth doing a dry run to find the "locked" position, and then to adjust the thickness of the washer so that the locked position does not leave the handle over the workpiece. (One of my idiosyncrasies!)

Howard

I skimmed the base of the handle.

N.