NSK 7306AW dimensions and technical reference
NSK 7306AW is a angular contact ball bearing reference with boundary dimensions 30×72×19 mm. The order is bore d × outside diameter D × bearing width B. Use the full marking and construction, not only the base number, when comparing candidates.
Contact angle, cage and complete marking
The catalogue base 7306A uses a 30° nominal contact angle (A). The standard W code identifies a pressed steel cage. The ratings below belong to this standard cage; optional cage codes are not extra products with automatically identical performance.
How this bearing locates the shaft
A single angular contact bearing carries combined loading with axial load in one direction. Radial loading also produces an axial reaction, so the surrounding arrangement needs an opposed bearing or equivalent verified support. A single bearing is not automatically a preloaded matched set.
Arrangement-specific load calculation
For Fr > 0 and Fa/Fr ≤ 0.80, P = Fr. Above that ratio, P = 0.39Fr + 0.76Fa. Static equivalent load is P0 = max(Fr, 0.5Fr + 0.33Fa). Fr and Fa are the applicable radial and axial loads in consistent units. Resolve reactions and load sharing for the actual bearing arrangement before using the formula; the factors alone do not establish safe machine loads.
Reading speed and lubrication data
The source gives a grease limiting speed of 7100 r/min. The oil limiting speed is 9500 r/min. These values are for the stated bearing version, not every cage or closure sharing the same dimensions. Near the limit, assess load, lubricant, temperature and heat removal; a catalogue speed is not a guaranteed continuous-duty speed.
Selection and mounting limits
- DB, DF and DT identify different matching arrangements, not user-created sets made safe merely by placing two loose bearings together. Verify the supplied set and clearance/preload specification.
- The catalogue omission rule refers to CN clearance for ordinary matched designations; it does not supply a numerical installed clearance, preload force or nut torque for this assembly.
- For a dash in the db column, NSK directs use of da minimum and ra maximum. The substitute applies to that mounting note, not to missing load or speed values. Follow the relevant single, DB or DF drawing; a DT shoulder layout is not fully specified here.
- A rating is a calculation reference, not an allowable load for an unspecified machine. Lubrication, fit, temperature, alignment and operating load still matter.
- This source does not establish machine fitment, replacement approval, a CAD file, friction torque or an installed preload. Missing values remain unstated rather than being copied from a similar model.
Technical basis:NSK Rolling Bearings for Industrial Machinery, E1103d (2025), Part C, C090–C091; construction and identification rules C072–C077. Source checked 2026-10-01. Independently organised technical reference, not a sales offer or interchange approval.
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Product specifications
Metric and imperial values are paired where the manufacturer provides both. Expand a section to review its parameters.
Core specifications8 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Variant / construction | Angular contact ball bearing | |
| Bore diameter | d | 30 mm |
| Outside diameter | D | 72 mm |
| Width | B | 19 mm |
| Basic dynamic load rating | C | 37 kN |
| Basic static load rating | C0 | 20.9 kN |
| Mass | ≈m | 0.346 kg |
| Cage | Pressed steel |
Boundary dimensions5 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Bore diameter | d | 30 mm |
| Outside diameter | D | 72 mm |
| Individual bearing width | B | 19 mm |
| Minimum bearing chamfer | r min. | 1.1 mm |
| Minimum secondary bearing chamfer | r1 min. | 0.6 mm |
Construction6 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Nominal contact angle | α | 30 ° |
| Standard cage code | W | |
| Optional cage codes — ratings require separate confirmation | (M), T | |
| Catalogue matching scope | DB, DF, DT | |
| Cage material and construction | Pressed steel | |
| Construction / arrangement | Single-row angular contact bearing |
Load ratings2 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Basic dynamic radial load rating | Cr | 37000 N |
| Basic static radial load rating | C0r | 20900 N |
Load-centre geometry1 parameter
| Parameter | Symbol | Value |
|---|---|---|
| Single-bearing effective load centre | a | 24.2 mm |
Lubrication-qualified speed2 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Limiting speed — grease | 7100 r/min | |
| Limiting speed — oil | 9500 r/min |
Mass reference1 parameter
| Parameter | Symbol | Value |
|---|---|---|
| Approximate mass | 0.346 kg |
Mounting dimensions — shown arrangement3 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Minimum shaft shoulder diameter | da min. | 37 mm |
| Maximum housing shoulder diameter | Da max. | 65 mm |
| Maximum adjacent fillet radius | ra max. | 1 mm |