NSK NJ260M dimensions and technical reference
NSK NJ260M is a single-row NJ-type cylindrical roller bearing with boundary dimensions 300×540×85 mm (bore d × outside diameter D × width B). This reference uses the catalogue row for NU260, the explicit NJ availability column and its standard cage. It is not a generic specification for every bearing with the same bore or base number.
Full designation and cage
The catalogue stem is NJ260. The standard cage code M completes the designation NJ260M; it identifies a machined brass cage.
Axial location and rib arrangement
The NJ arrangement can locate the shaft in one axial direction. Axial loading is limited and needs a separate assessment; radial ratings are not axial capacity values.
Load ratings and operating speed
Basic dynamic radial rating Cr is 1730 kN and basic static radial rating C0r is 2070 kN. These are reference ratings for calculation, not allowable machine loads. Both the load ratings and speed values on this page apply to the standard cage; a listed optional cage does not inherit these values without confirmation.
The grease limiting speed is 1100 r/min; the oil-bath limiting speed is 1300 r/min. The thermal oil-bath rating and forced-oil mechanical limit are separate operating references. A dash in the source means not stated, not zero. Load, heat removal, lubricant and duty determine whether a catalogue speed is suitable.
Mounting and selection limits
- Read shoulder diameters and fillet radii with the matching NU/NJ/NUP or N/NF mounting arrangement. The db maximum refers to an adjusting ring for NU and NJ, not a universal shaft shoulder.
- NSK requires increasing da and reducing Da from the tabulated values when axial loads apply. The table does not specify the amount for your assembly, so these figures do not approve an axially loaded installation.
- Mass is printed once for a shared catalogue row. It is retained as a reference, not claimed as an individually verified mass for each rib arrangement.
- ISO Normal follows the omitted precision-suffix rule. The clearance omission rule depends on whether the design is interchangeable; this page does not assert a numerical CN, C3 or CC clearance range.
- Very light loads can cause roller slip and smearing. Shock, vibration, lubrication and alignment must be considered; size matching alone does not establish a substitute.
- An NJ bearing plus a suitable HJ thrust collar is an NH arrangement. No collar designation or complete NH assembly is established by this row. Double-row NN/NNU products and other cage or clearance variants are not covered.
- No machine fitment, CAD model, seal performance or installed preload is established here. Confirm the complete marking and application before using the data.
Technical basis:NSK Rolling Bearings for Industrial Machinery, E1103d (2025), Part C, C154–C155; construction, designation rules and operating cautions C126–C129. 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 specifications7 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Variant / construction | Cylindrical roller bearing | |
| Bore diameter | d | 300 mm |
| Outside diameter | D | 540 mm |
| Width | B | 85 mm |
| Basic dynamic load rating | C | 1730 kN |
| Basic static load rating | C0 | 2070 kN |
| Cage | Machined brass |
Boundary dimensions6 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Bore diameter | d | 300 mm |
| Outside diameter | D | 540 mm |
| Bearing width | B | 85 mm |
| Minimum bearing chamfer | r min. | 5 mm |
| Minimum secondary bearing chamfer | r1 min. | 5 mm |
| Roller inscribed circle diameter | Fw | 364 mm |
Catalogue reference mass1 parameter
| Parameter | Symbol | Value |
|---|---|---|
| Approximate shared-row mass — not separately stated for each rib arrangement | 89.2 kg |
Construction8 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Single-row construction type | NJ | |
| Rib arrangement | Two outer-ring ribs; one inner-ring rib | |
| Standard cage material | Machined brass | |
| Standard cage marking | M | |
| Other cage codes listed for this catalogue row | None listed in this row | |
| Precision — designation omission rule | ISO Normal when no precision suffix is specified | |
| Clearance identification — verify interchangeability | No clearance suffix shown. CN omission applies to interchangeable designs; do not infer a numerical clearance. | |
| Optimized crowning note | No optimized-crowning asterisk on this row |
Load ratings — standard cage2 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Basic dynamic radial load rating | Cr | 1730000 N |
| Basic static radial load rating | C0r | 2070000 N |
Lubrication-qualified speed — standard cage4 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Thermal speed rating — oil bath | 1200 r/min | |
| Mechanical limiting speed — forced oil circulation | Not stated in this catalogue row | |
| Limiting speed — grease | 1100 r/min | |
| Limiting speed — oil bath | 1300 r/min |
Mounting dimensions — shown arrangement5 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Minimum shaft shoulder diameter | db min. | 320 mm |
| Maximum housing shoulder diameter | Da max. | 520 mm |
| Maximum adjusting-ring diameter (NU/NJ arrangement) | db max. | 358 mm |
| Maximum adjacent fillet radius | ra max. | 4 mm |
| Maximum secondary adjacent fillet radius | rb max. | 4 mm |