Thrust ball bearings are specifically designed to handle axial (thrust) loads only and are not suitable for radial loads. The LD-404 single-direction thrust bearing consists of three main components: a shaft washer (inner ring with a raceway), a housing washer (outer ring with a raceway), and a ball and cage assembly containing the rolling elements. The shaft washer is mounted on the rotating shaft, while the housing washer sits in the stationary housing. This separable design allows for easy installation and disassembly, and the two washers can be handled independently during assembly.

The LD-404 series includes the 51100, 51200, 51300, and 51400 single-direction series, representing progressively increasing load capacities. The 51100 series is the light-duty option with the smallest profile, the 51200 series is the most commonly used medium-duty thrust bearing, the 51300 series provides heavy-duty capacity with more balls and larger washers, and the 51400 series offers the highest axial load ratings. Bore diameters range from 10mm to 150mm, with outer diameters from 24mm to 250mm and overall heights from 9mm to 60mm. Double-direction thrust bearings (52200/52300 series) are also available for applications requiring axial load support in both directions.

Manufactured from high carbon chromium bearing steel (GCr15/SUJ2), the bearing washers and balls are through-hardened and precision-ground to ensure flat, accurate raceways that distribute the axial load evenly across all balls. The stamped steel cage provides reliable spacing and guidance of the balls, while machined brass cages are available for applications requiring higher strength or corrosion resistance. Black oxide surface treatment is available for additional corrosion protection and improved break-in characteristics.

It is important to note that thrust ball bearings have significant speed limitations compared to radial bearings due to centrifugal forces acting on the balls at higher rotational speeds. They are best suited for low-to-moderate speed applications where the primary load is purely axial, such as vertical pumps, jack screws, automotive clutch mechanisms, crane hooks, and rotary tables. For high-speed axial load applications, angular contact ball bearings or tapered roller bearings are generally more appropriate. Proper mounting requires the bearing to be aligned perpendicular to the shaft axis to ensure uniform load distribution across all rolling elements.