The Timken Company NA861 Tapered Roller Bearing Cone

Description:

The Timken NA861 is a precision tapered roller bearing cone (inner ring assembly) engineered for use in heavy-duty double-row tapered roller bearing configurations. The NA861 cone is designed to mate with the compatible Timken 854D double cup (outer ring) to form a complete TNA (Tapered Non-adjustable Double Row) bearing assembly capable of supporting exceptionally high combined radial and axial loads. Commonly installed in industrial gearboxes, conveyors, mining equipment, construction machinery, agricultural equipment, and power transmission systems, this tapered roller bearing cone provides accurate shaft alignment, excellent load distribution, and reliable long-term performance in demanding industrial environments. Maintenance teams, OEMs, and system integrators specify the Timken NA861 tapered roller bearing cone for equipment repair, replacement, machine rebuilds, and retrofits where genuine Timken matched bearing components are required.

Applications:

The Timken NA861 tapered roller bearing cone is designed for heavy-duty industrial applications requiring high load capacity and precise shaft support. When matched with the Timken 854D double cup, it is widely used in industrial gear reducers, heavy-duty conveyors, mining and aggregate equipment, construction machinery, agricultural equipment, and power transmission systems where the complete double-row bearing assembly provides exceptional radial and axial load capacity, accurate shaft positioning, reduced friction, and extended service life.

Technical Specifications:

• Manufacturer: Timken
• Manufacturer Part Number (MPN): NA861
• Product Type: Tapered roller bearing cone
• Bearing Type: Double-row tapered roller bearing cone (inner ring assembly)
• Series: TNA (Tapered Non-adjustable Double Row)
• Design Series: TNA
• Cone Part Number: NA861
• Bore Diameter: 4.0000 in (101.600 mm)
• Inner Ring Width (B): 2.2650 in (57.531 mm)
• Cage Type: Stamped steel
• Material: High-grade bearing steel
• Load Type: Combined radial and axial loads
• Dynamic rating: 179,000 lbf (797,000 N)
• Static rating: Refer to complete bearing assembly specification
• Dynamic axial rating: 15,300 lbf (68,000 N)
• Weight: Approximately 32.3 lb (14.65 kg)
• Compatible cone/cup: Timken NA861 cone with Timken 854D double cup

Common Replacements:

• Timken NA861/854D bearing assembly
• Timken NA861-90031 bearing assembly
• Timken NA861-90050 bearing assembly