NACHI 51220 Thrust Ball Bearing

NACHI 51220 Thrust Ball Bearing

The NACHI 51220 is a single-row light series thrust ball bearing with a flat back-face housing washer for rigid, concentric mounting, featuring a bore diameter of 100 mm, outer diameter of 150 mm, and height of 38 mm. Single-direction thrust ball bearings are designed to sustain axial loads in one direction and locate a shaft axially in one direction – making them ideal for applications requiring precise axial positioning under purely axial or predominantly axial loading.

Design & Construction

Manufactured by NACHI (a division of Fujikoshi Corporation, Japan), the 51220 consists of a shaft washer, a housing washer, and a ball and cage assembly. The flat back-face housing washer provides a rigid, stable interface with the bearing housing, suitable for applications where precise shaft-to-housing alignment is maintained. Washers and balls are precision-ground from high-carbon chromium bearing steel (AISI 52100 / JIS SUJ2), heat-treated to achieve optimum hardness and fatigue life. The pressed steel cage retains the balls at uniform spacing for consistent load distribution and quiet operation.

Performance

Rated for a basic dynamic axial load capacity of 146.0 kN and a static axial load capacity of 410.0 kN, this bearing delivers reliable performance under sustained axial loading. Permissible speeds reach 1,300 rpm with grease lubrication and 1,900 rpm with oil lubrication. A minimum axial load must be maintained during operation to prevent ball skidding and ensure proper rolling contact between the balls and raceways.

Typical Applications

• Machine tool spindles and lead screws
• Automotive steering columns and clutch release mechanisms
• Crane hooks, slewing rings, and lifting equipment
• Gearbox thrust faces and differential assemblies
• Pump shafts and compressor thrust loads
• Vertical shaft arrangements and turntable supports
• Jack screws, presses, and actuators
• Agricultural and industrial transmission shafts