Bearings
A spindle rebuild is only as good as the bearings going back in it, and angular contact bearings are the component most responsible for controlling runout, thrust load, and heat generation at high RPM. HS Spindles stocks angular contact bearings from 10mm to 50mm bore in P4 and P4+ precision grades, in both open (CTA) and sealed (2RZ) configurations, matched to common high-speed spindle designs. Bearing selection comes down to three things: bore size (matched to your spindle’s shaft), precision grade (P4 for most production spindles, P4+ where tighter runout is required), and sealing style (2RZ where contamination control matters more than the marginal speed loss from added seal drag). Installing the wrong precision grade is one of the most common causes of a rebuilt spindle running hotter or noisier than expected, even when every other component is correct. Match bore size and grade to your spindle’s OEM bearing spec before ordering, and always replace bearings in matched sets rather than mixing old and new.
