Angular contact ball bearings feature raceways on both the inner and outer rings that are offset relative to each other in the axial direction, creating a contact angle between the ball and the raceway. This design enables the bearing to support combined radial and axial loads simultaneously, with the axial load capacity increasing as the contact angle increases. The LD-403 series is available with standard contact angles of 15 degrees (C type), 25 degrees (AC type), 30 degrees (B type), and 40 degrees (A type), allowing selection based on the specific ratio of radial to axial load in the application.

The LD-403 series covers the 7000, 7200, 7300, and 7400 series, representing ultra-light, light, medium, and heavy-duty configurations. Bore diameters range from 10mm to 100mm to suit a wide variety of shaft sizes. These bearings are designed for high-speed operation with low friction and heat generation, making them ideal for applications such as machine tool spindles, pumps, compressors, and electric motors. The precision-ground raceways and balls ensure smooth, quiet operation with minimal vibration.

For applications requiring even higher speeds or electrical insulation, ceramic hybrid versions with silicon nitride (Si3N4) balls are available. Ceramic balls are significantly lighter than steel balls, reducing centrifugal force and friction at high speeds, while also providing superior corrosion resistance and electrical insulation properties. Cage options include nylon (PA66) for quiet high-speed operation, machined brass for heavy-duty and high-temperature applications, and stamped steel for general-purpose use. The LD-403 series is available in ABEC 3 through ABEC 7 precision grades for applications ranging from industrial machinery to ultra-high-precision equipment.

Angular contact ball bearings are frequently used in paired or matched set arrangements to handle axial loads in both directions and to provide increased rigidity. Common arrangements include back-to-back (DB) for maximum moment stiffness, face-to-face (DF) for easier installation and tolerance to misalignment, and tandem (DT) for increased axial load capacity in a single direction. Factory-matched sets are available with controlled preload or clearance specifications to ensure optimal performance without requiring on-site adjustment.