uxcell R188ZZ Deep Groove Ball Bearings Z2 1/4 Inch x 1/2 Inch x 3/16 Inch Double Shielded Chrome Steel Skateboard Bearings Sealed Industrial Bearings10pcs

I've used these to fix a globe and make a few fidget spinners. They spin great and seem to last.

AKA: The “You Didn’t Know You Needed These Until You Did” BearingsThese R188ZZs are the sleeper MVPs of anything that spins. I grabbed them for a 3D printed mini turbine project, and they’ve since found their way into a fidget spinner rebuild, a sliding drawer mod, and even a DIY rotary encoder test rig. They're shielded, compact, and smooth as silk when installed properly.Z2 tolerance means you’re getting solid mid-grade precision—not quite aerospace, but plenty good for most hobby and light industrial builds. Pop these into a printed housing or bearing block, and they’ll quietly spin forever while you admire how much smoother everything feels.

I purchased these for very light, occasional duty. I would not recommend for mission-critical or even long term use. For me, they work fine but these are definitely in the "buyer-be aware" category.

These were slightly undersized on the outer diameter, but didn't cause any issues on my project due to not boring the holes until the bearings arrived. These bearings also have a lot of lateral movent, and will look like they are about to come apart with light side loading. They did however hold up to being assembled with a .001 press fit bore and shaft. The bearings are smooth, not rough or gritty, and have decent metal sheilds. They are decent little bearings, but I personally couldn't recommend these bearings for high speed, robotics, anything CNC, or 3D printing.

Have only used them in light duty applications but they have been fine. Hard to believe the price..

I bought these to replace the damaged bearing in my fidget spinner. They are okay. Just okay. They rotate smooth and are decently quiet, but they maintain no momentum. The moment you stop applying force, they'll stop rotating. The bearings I had before could rotate for well over five minutes with a single strong flick. This go two seconds at most, and I wish that was an exaggeration.I don't know if it's because they have a lot of grease/lubricant in them or what, but generally I'm disappointed with them. If you just need something that turns smoothly when pressure is applied, these will do great. They fit as expected and would be well priced for that purpose. But if you need it to keep spinning, then these ain't it.

Did not use yet.

Feels like there is grit inside every single one.