Hi,

I picked up a couple of lenghts of ballscrew that I am hoping to use in DIY CNC machine. They had a nominal o/d of about 16mm and a pitch of 5mm. I presumed it was SFU1605 and ordered a couple of chinese ball nuts to fit. They don't !

They were obviously not just slack but the wrong dimension , so I pulled the balls out and find that they are 3.175mm ie 1/8" . This seemed odd but looking at spec of chinses ballscrew assemblies this is apparently not uncommon. However SFU1605 has an inner track diameter of 12mm.

Measuring my bar with two balls each side I find 19mm ( 19.05 is 3/4" )

So it appears that my ballscrew has 1/2" i/d 1/8" balls and 5mm pitch.

Can anyone help identify this? I've never come across this kind of hybrid before.

If not I'll have to dump the bar and buy two complete assemblies. Which would be a bummer since I have two 3ft lengths and that will cost a packet..

TIA. Reg.