1. Product Overview The 7007CDB back‑to‑back (DB) duplex angular contact ball bearing is assembled by two pre‑ground single 7007CD bearings with 15‑degree CD contact angle. DB pairing structure provides excellent moment rigidity, bears combined radial load and bidirectional axial loads. Factory pre‑preloaded design avoids manual pairing error for high‑speed precision rotary equipment. It is widely used for high‑speed machine tool spindles, high‑frequency motors and precision