I bought these for hobby applications and they work OK - not exactly free spinning like the fidget spinner type bearings that are around, and I have used them for a couple of 3D printing

The bearings were heavily greased to the point of no free spin

About 5 spin well, rest are just mediocre.

The center bore wasn't always exactly centered and several spun 'rough' but did work and will be sufficient for my needs

Will keep them and use them for something, just was hoping for a bearing that was a little smoother and free spinning.

well so far, some have what feels like metal bits in them that prevents super smooth spin