6324-M (brass cage) bearing: complete specifications & equivalents
The 6324-M is a ISO 15 radial bearing sized 120 x 260 x 55 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 120 mm |
| Outer diameter D | 260 mm |
| Width B | 55 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 208 kN |
| Basic static load rating C0 | 186 kN |
| Fatigue load limit Pu | 5.7 kN |
| Reference speed (thermal) | 5600 rpm |
| Limiting speed (mechanical) | 5000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 14000 g |
| Manufacturer designation | 6324 M |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 6300-series range
| Bore d | 4.724 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 2.165 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in 6300-series | 2 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 3–95 mm |
| Bore position in 6300-series (smallest first) | 30 of 40 |
| Bore above smallest 6300-series size | 118 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6324-2RS-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6324DDU on the same 120×260×55 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6324-ZZ-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6324ZZ on the same 120×260×55 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6324-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6324 on the same 120×260×55 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6324-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | NTN bearing 6324 on the same 120×260×55 mm envelope, but catalogue C/C0 differ (208/186 kN vs 229/185 kN) — envelope interchange only after a load check. |
| 6324-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | NTN bearing 6324LLU on the same 120×260×55 mm envelope, but catalogue C/C0 differ (208/186 kN vs 229/185 kN) — envelope interchange only after a load check. |
| 6324-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | NTN bearing 6324ZZ on the same 120×260×55 mm envelope, but catalogue C/C0 differ (208/186 kN vs 229/185 kN) — envelope interchange only after a load check. |
| 6324 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6324 (open arrangement) shares the 120×260×55 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
| 6324-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6324-2RS1 (two contact elastomer seals) shares the 120×260×55 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
| 6324-ZZ | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6324-2Z (two non-contact shields) shares the 120×260×55 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 6324-M model number is decoded
In the 6300-series, the last two digits encode the bore: 6324 carries code 24 = 120 mm (code × 5). The envelope is 120×260×55 mm (4.724×10.236×2.165 in) with a 70.0 mm radial section height, C 208 kN, C0 186 kN and Pu 5.7 kN. The open 6324 M carries no shields or seals and relies on application lubrication and external sealing. The M suffix identifies the machined brass cage execution, a separate order number from the pressed-steel version. Limiting speed 5000 r/min, catalogue mass 14000 g.
Typical equipment & failure modes
Common applications
- gearboxes and speed reducers
- centrifugal and positive-displacement pumps
- material-handling equipment
- industrial fans
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- cage damage from running beyond the limiting speed
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Deep-groove geometry tolerates only minutes of misalignment; if the 260 mm housing bore cannot be aligned, move to a self-aligning bearing rather than shimming 6324-M.
- Clearance suffixes follow the seal code in the designation stack (e.g. 6324-2Z/C3 in SKF spelling); no suffix means normal CN internal clearance.
- The M suffix on 6324-M denotes a machined brass cage: it is the choice for high speeds, marginal lubrication and shock/vibration duty, and it is temperature-tolerant where polymer cages are not — the 14000 g quoted mass includes the heavier cage.
- Open 6324-M needs external sealing at the arrangement level; in dusty housings its life depends entirely on those external seals and the regreasing schedule.
- Plan a relubrication interval for 6324-M; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Catalogue ratings for 6324-M (C 208 kN, C0 186 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
- For positions that need relubrication, choose the open execution of 6324 and design the housing with a grease path; shielded and sealed versions are intended as fit-and-forget units.
- Where two 6324 bearings share one shaft in a preloaded or matched arrangement, order both from the same production lot; catalogue figures describe a single bearing, not a matched set.
Frequently asked questions
What are the dimensions of 6324-M?
The SKF 6324 M measures 120 mm bore × 260 mm OD × 55 mm width (4.724 × 10.236 × 2.165 in), mass about 14000 g. It is open, with no shields or seals.
How does the bore code in 6324 work?
The final two digits of 6324 are bore code 24, multiplied by 5 to give 120 mm.
What internal clearance does 6324-M have?
Standard supply is normal CN radial clearance unless a suffix states otherwise; for tight fits or hot shafts SKF lists the C3 execution of the same size — the residual clearance left after mounting is what governs running life.
How long can a greased 6324-M be stored?
Sealed and shielded SKF units carry a finite grease shelf life: SKF recommends first-in-first-out stock rotation and dry, cool, vibration-free storage. Open units ship with rust preventive only and are greased at assembly.
What load can 6324-M take?
Catalogue values for 6324 M: dynamic C 208 kN, static C0 186 kN, fatigue limit Pu 5.7 kN. Use C in life calculation and C0 for static checks at 120 mm bore.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.