What best ball bearing features should I look for?
- HIGH DIMENSIONAL ACCURACY – There are various sets of tolerances for the boundary dimensions (ID, OD, width) of bearings, as well as the characteristics of the balls. Most standard bearings meet ABEC 1, the lowest set of tolerances. Higher-precision bearings hold to ABEC 3 or better.
- HONED RACEWAYS – Ball paths should not just be ground, but honed to a smoother finish. Smoother ball paths mean smoother, quieter, longer life.
- PRECISION BALLS – Standard bearing balls are Grade 25, or up to 0.000025” from perfect roundness. Precision bearings use Grade 10 balls, or within 0.000010” from perfect roundness.
- QUIET AND SMOOTH RUNNING – At high speeds and loads, even minor noise and vibration can be greatly magnified. Ball bearings should be tested for vibration and noise, both before and after lubrication.
- GREASE – Grease is the lifeblood of a bearing; it needs to be able to handle high temperatures and high loads without breaking down.
- STEEL RETAINER – An all-steel retainer will be stronger, more heat-resistant, and more rigid than a plastic retainer.