NTN NB387A Tapered Roller Bearing Cone Bearings & Seals

The NTN NB387A is a precision-engineered tapered roller bearing cone designed for heavy-duty automotive and trailer applications. This single row bearing cone features a 57.15mm (2.25 inch) bore diameter and 21.946mm cone width, making it ideal for axle and hub assemblies requiring high load capacity and reliable performance.

Key Features:

• Case-carburized alloy steel construction for superior fatigue life and durability
• 57.15mm bore diameter with 3.6mm maximum shaft fillet radius
• Dynamic load rating of 82,500N and static load rating of 105,000N
• Precision heat treatment and surface finishing for consistent performance
• Temperature range: -40°C to 120°C (-40°F to 248°F)
• Compatible with Dexter 10,000 lb general duty axles

This bearing cone is commonly used as an inner bearing for Dexter hub assemblies including 8-288-3 and 8-430-5 models, and as an outer bearing for 8-214-5 and 8-214-6 hubs. The NB387A meets bearing quality standards and is designed for high-speed operation in demanding trailer, RV, and heavy-duty vehicle applications. NTN's rigorous quality control ensures dimensional accuracy and reliable bearing performance across the full operating temperature range.