NACHI 7311 Angular Contact Ball Bearing

NACHI 7311 Angular Contact Ball Bearing

The NACHI 7311 is a precision single-row angular contact ball bearing designed to carry combined radial and axial loads simultaneously. With a bore diameter of 55 mm, outer diameter of 120 mm, and a width of 29 mm, this bearing conforms to ISO dimension standards and is a direct interchange for equivalent angular contact bearings from other manufacturers.

Design & Construction

Manufactured by NACHI – one of Japan’s leading bearing producers – the 7311 is precision-ground from high-carbon chromium bearing steel (AISI 52100 / JIS SUJ2), heat-treated to achieve optimum hardness and fatigue resistance. The raceways are offset in the inner and outer rings to create an angular contact geometry that enables the bearing to support axial loads in one direction in addition to radial loads. The standard 30-degree contact angle provides an effective balance between radial and axial load capacity, handling combined loads efficiently in a wide range of general-purpose applications.

Performance

Rated for a basic dynamic load capacity of 85.5 kN and a static load capacity of 61.5 kN, this bearing delivers dependable load-carrying ability and long calculated service life under correct operating conditions. Permissible speeds reach 5,000 rpm with grease lubrication and 7,000 rpm with oil lubrication, making it well suited to high-speed rotating equipment. Angular contact ball bearings may be mounted singly for combined loads, or in matched pairs (back-to-back DB, face-to-face DF, or tandem DT arrangements) for increased rigidity and bi-directional axial load support.

Typical Applications

• Machine tool spindles and precision equipment
• Pumps, compressors, and blowers
• Gearboxes, reducers, and transmission assemblies
• Electric motors and generators under combined loading
• Agricultural and farming equipment
• Automotive wheel hubs and drivetrain components
• Conveyor and material-handling systems
• HVAC fans and air-conditioning units
• Food and beverage processing machinery
• General industrial and workshop machinery