CNC Linear Way Rail Kit Set - 2pcs Fully Support SBR 12-500mm 12mm Ball Bearing Linear Slide Rail Shaft + 4pcs SBR12UU Blockbearing

The bearing blocks slide just fine, one of mine was a bit tough to get on. The cap screws holding the rail to the guide block are absolutely awful. Many of mine were stripped when I got the rails, so they would just fall out. Count on replacing them as soon as you buy this. Just hoping I don't have to re-tap the holes too...EDIT: I took all the screws out and inspected the rail. It wasn't even tapped fully, there was just ONE thread for the screw to thread into and then bare metal after that. No wonder the screws all stripped, there was no thread for them to work into. Horrible quality build, spend a bit more elsewhere to get rails that actually work. I will have to try to tap the holes myself now, and if this doesn't work I'll have to resort to buying a completely new set. Would vote 0 stars if possible.

It will work for what I need but not overly impressed for the price. Rails seem okay, hole drilling is not accurately placed so I had to compensate in my design. The bearings however are quite awful. Loud and not smooth even with grease, the seal was chewed up and the balls fall out quite easily compared to other LM style bearings I’ve bought before. The tapped holes on them needed to be cleared out with a tap to thread a m5 machine screw into. One came missing the set screw that stops the bearing from rotating in the housing. Again, they will work for my purposes (small CNC router), but don’t expect name brand quality here.

Marginal quality for my application which does not require very smooth operation. Bearings are very rough despite adjustment attempts and additional grease. Bearing housings have inconsistent dimensions. Rails are good.

Bearings not fitting properly with the shafts.

aiguiser

Good