SKF 71909CD P4ATBTA Super Precision Ball Bearing

SKF 71909CD/P4ATBTA is a set of three super‑precision angular contact ball bearings designed for high‑speed, high‑accuracy spindle service. The TBTA designation indicates three bearings arranged back‑to‑back and tandem, with an extra-light preload (A) to provide symmetrical preload and improved stiffness across the set. Each bearing measures 45 mm bore, 68 mm outer diameter, and 12 mm width, and the trio is supplied as a set of 3 for matched performance in precision spindle assemblies. The bearings feature a 15° contact angle, are open (unsealed), and carry ISO P4A tolerance class for tight running accuracy in demanding machine tools. This configuration is commonly used in high‑precision CNC lathes and milling machine spindles where precise radial and axial load handling is required.