I have stumbled upon several various sets of linear rails by different Mfgs. that has come on the market reasonably priced...
These Mfgs. include THK and Rexroth along with NSK
Are the THK as good of a rail and block as say the Hiwin...Or the Rexroth vs the NSK Are any of these three comparable to what seems the highly sought after Hiwin?
I can get these a bit more than the China versions which seems to be readily available.
I read on the packaging that the THK we made in Japan and under the impression they were quality blocks and rails?

Along with an addition question,
Example: if I was ordering a 1000mm rail I would assume that the rail from one end to another would be 1000mm
then If I ordered a 1000mm screw would the screw measure 1000mm from the outer side of the BF and BK blocks?
or
Measure from one end to the other
So If I wanted my OVAL screw to measure the from the outer side of the BK/BF to be the same as my 1000mm rail should I add? And if so how much?
Thanks
Paul