Precision Parts 387A Tapered Roller Bearing Cone Bore Bearings & Seals - 2.25

The Precision Parts 387A is an imperial single-row tapered roller bearing cone designed for demanding automotive, trailer, and industrial applications. With a 2.250" inner diameter (bore), it pairs with the 382A cup (outer race) to form a complete tapered roller bearing assembly capable of handling combined radial and axial (thrust) loads.

This bearing is a widely used industry-standard part, commonly specified as the inner bearing on 9,000 lb and 10,000 lb Dexter general-duty axles, and is also used as the outer bearing on certain Dexter hub assemblies. Compatible hub applications include Dexter 8-288-3, 8-430-5, 8-214-5, and 8-214-6 hubs.

Key Specifications:

• Bearing Type: Single-Row Tapered Roller Bearing Cone (Inner Ring Assembly)
• Inner Diameter (Bore): 2.250 in (57.15 mm)
• Outer Diameter: 3.813 in (96.84 mm)
• Cone Width: 0.864 in (21.95 mm)
• Overall Bearing Width (with 382A cup): 0.827 in (21.00 mm)
• Matching Cup/Race: 382A (sold separately)
• Bearing Material: Case-Carburized Steel
• Precision Rating: Class 2 (ABMA)
• Operating Temperature Range: -40°F to 250°F

Features & Benefits:

• Designed to meet or exceed OEM specifications for reliable, long-service performance
• Tapered roller geometry provides superior handling of combined radial and single-direction thrust loads
• Case-carburized steel construction delivers excellent fatigue resistance and extended service life
• Conical rollers and raceways converge at a common apex for optimized load distribution
• Suitable for high-speed trailer, automotive, agricultural, and industrial applications
• Industry-standard part number cross-references with Timken 387A, National 387A, and other major brands

The 387A is an industry-standard bearing cone referenced across multiple manufacturers including Timken, National, NTN, and others. It is sold as the cone (inner ring) only — the matching 382A cup/race is sold separately.