10PCs LM8SUU Linear Ball Bearing Nickel Plated 8mm x 15mm x 17mm for 8mm Linear Motion Shaft for 3D Printer and CNC Machine

Admittedly these bearings aren't industrial quality, but they were cheap, and they're definitely better than the bearings I had! They don't roll extremely smoothly, but still work well about 200 hours later.

Good if you add a little teflon dry lube or something like that.

I purchased a number of linear bearings on Amazon and these run as smooth or smoother than any I've purchased

I didn't need 10 of these but it's good that I bought them. Quality control seems lacking. Of the 10, two seemed misaligned causing them to stick and bind and two were too loose. The other six were usable. So about 40% of them were bad.The price is cheap and so I don't mind too much. If you need 6 or less, buy the set of 10 so you can pick and choose and improve your changes of getting good ones.

These need to be greased (super lube silicone based grease) and they aren't perfectly clean so they will shed some dirt for a bit, which you can wipe away.

Starting to thing there are no good bearings on amazon. Tested 3 of these so far and 2 failed in spectacular fashion already. So grindy they won't even move down the rod without a real decent amount of force even after working them in. ANY side twist at all and it locks to the linear bar. Even if all the rest were perfect, this is a 20% failure and in machining that is not acceptable. These companies need to get some QC before they are allowed to sell on Amazon in the future.But thats just my opinion as a fabricator/machine operator with standards and 20 years of experience, others may disagree.

I have an old 3d printer that the original bearings were damaged from the get go. They did function for a few years but just lately it shot out almost all bearings as the z axis went down. These guys work great.

Sturdy bearings for small tasks. I was surprised over the weight of them. They’re pretty heavy and hold up well to stress