The NSK HR30306J Tapered Roller Bearing is a high-quality metric tapered roller bearing engineered for combined radial and axial load support in mechanical and automotive systems. Featuring precision construction and a robust tapered design, it delivers long service life and reliable performance in assemblies where moderate radial loads and thrust are present.

Technical Specifications

This bearing includes both the cone (inner ring + rollers + cage) and cup (outer ring) which must be assembled together for correct installation.

Product Overview

Tapered roller bearings are engineered so that the rollers and raceways converge at a common apex, allowing them to support:

✔ Heavy radial loads
✔ Axial thrust loads in one direction
✔ Combined load conditions with optimal rigidity and service life

The “J” suffix in the HR30306J designation indicates that the bearing conforms to ISO dimensional standards for roller and raceway geometry, ensuring interchangeability and consistent performance.

Features & Benefits

✔ High Load Capacity: Designed to handle combined radial and axial loads efficiently.
✔ Robust Construction: Hardened steel rollers and raceways for long life under load.
✔ Standard Metric Size: Easy to match with other ISO 30306 series bearings.
✔ Moderate Speed Capability: Suitable for rotating systems with grease or oil lubrication.
✔ Separable Cone & Cup: Allows precise assembly and preload adjustment.

How to Match to Your Vehicle (Fitment Guide)

Important: There is no official published list tying HR30306J directly to specific vehicle makes/years because this bearing is selected in automotive systems by dimension, load, and OEM bearing code — not by a generic size alone. Modern parts catalogs reference bearings by OEM part numbers, which then correspond to specific dimensions like 30 × 72 × 20.75 mm.

To confirm fitment for your car, truck, or machinery:

1. Check the OEM Bearing Code on your vehicle’s original bearing or parts manual.

2. Verify Dimensions: Confirm the required bearing size is 30 mm bore × 72 mm outer × 20.75 mm width.

3. Check Load & Rotation Requirements: Match RPM and load conditions to the HR30306J ratings.

When a vehicle’s service manual calls for a metric tapered bearing with these exact dimensions, the NSK HR30306J is a direct replacement.

⚙️ Common Automotive Areas Where This Size May Be Used

This bearing size is frequently found in systems such as:

• Wheel hub assemblies (paired with another tapered bearing)

• Transmission auxiliary shafts

• Differential pinion support bearings

• Steering knuckle supports

• Axle or drive shaft bearing support

These are typical bearing uses when a 30306 series (metric 30×72×20.75 mm) bearing is specified in an OEM parts diagram — always cross-check with your vehicle’s parts list.

Industrial & Machinery Applications

Beyond automotive fitment, the HR30306J is widely used in:

• Industrial gearboxes

• Conveyors and rotary machinery

• Pumps and compressors

• Agricultural and construction equipment

• Motor shafts where axial load support is needed

Such applications also rely on dimension and load matching, making this tapered bearing versatile beyond vehicle use.

Related / Equivalent Bearings

If you’re searching for cross-brand or dimension-matched equivalents (same 30×72×20.75 mm size), consider:

• SKF 30306 series metric tapered roller bearings

• NTN 30306 metric equivalents

• Timken 30306 series

• KOYO 30306 series

⚠ Always confirm exact dimensions and load ratings before substituting between brands.

Fitment & Installation Notes

✔ Use as a paired bearing if supporting axial loads in both directions.
✔ Ensure correct preload or clearance per assembly design.
✔ Use proper grease or oil lubrication based on speed, temperature, and environment.
✔ Verify shaft/housing tolerances match bearing abutment dimensions.