I'm in the design stage for an adjustable table machine and considering using this stuff:

http://www.zappautomation.co.uk/sfc2...ound-rail.html

as a linear guide when raising lowering the table.

But I would need a thread cut onto one end of a 400mm-500mm piece of rod. Could someone ballpark me a cost for getting one of these threaded please?

PS If I have completely lost you, look at this video and picture the table moving up and down on 20mm steel rods instead of wooden legs:
https://www.youtube.com/watch?v=LKUVgv_iLtM

Thanks.