2318-K bearing: complete specifications & equivalents
The 2318-K is a ISO 15 radial bearing sized 90 x 190 x 64 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 90 mm |
| Outer diameter D | 190 mm |
| Width B | 64 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 151 kN |
| Basic static load rating C0 | 57 kN |
| Fatigue load limit Pu | 2.5 kN |
| Reference speed (thermal) | 6300 rpm |
| Limiting speed (mechanical) | 4500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 8450 g |
| Manufacturer designation | 2318 K |
| 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 & 2300-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 7.48 in |
| Width B | 2.52 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 50 mm |
| Smallest bore in 2300-series | 10 mm |
| Largest outer diameter in 2300-series | 215 mm |
| Width range across 2300-series | 17–73 mm |
| Bore position in 2300-series (smallest first) | 19 of 21 |
| Bore above smallest 2300-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 2318 | NTN | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
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 2318-K model number is decoded
The 23xx series is the wide medium-section self-aligning ball bearing (ISO dimension series 23). the last two digits encode the bore: 2318 carries code 18 = 90 mm (code × 5). Envelope 90×190×64 mm (3.543×7.48×2.52 in) with a 50.0 mm radial section height, C 151 kN, C0 57 kN and Pu 2.5 kN. The open 2318 K carries no shields or seals and relies on application lubrication and external sealing. The suffix identifies the glass-fibre-reinforced polyamide 66 cage execution. The K suffix marks a 1:12 tapered bore for direct mounting on a tapered shaft or with an adapter sleeve. Reference (thermal) speed 6300 r/min, limiting speed 4500 r/min, catalogue mass 8450 g.
Typical equipment & failure modes
Common applications
- industrial electric motors
- conveyor drum and pulley shafts
- agricultural gearboxes
- textile machinery drives
Known failure patterns
- lubricant starvation where no regreasing interval is maintained
- contamination wear when the open arrangement is used without adequate external sealing
- incorrect sleeve tightening that leaves the tapered bore loose or over-expanded, changing internal clearance
- adapter-sleeve fretting when the sleeve is not locked against the shaft shoulder
- cage damage from running beyond the limiting speed
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Assign interference to the rotating ring: on a 90 mm rotating shaft use a k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
- Mount 2318-K by heating the inner ring (max 120 °C) on a cylindrical bore — driving it home through the outer ring or balls brinells the raceways.
- Tighten the adapter sleeve to the SKF-recommended starting clearance, not to feel — an over-tightened sleeve expands the inner ring and removes all internal clearance.
- The suffix on 2318-K denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 4500 r/min limiting speed, but it softens above roughly 120 °C — check the oil temperature in hot drives.
- Fillet radii must clear the 2318-K chamfer so the 64 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 2318-K (2RS1) allows less — the lip seal binds before the spherical raceway does.
Frequently asked questions
What are the dimensions of 2318-K?
SKF 2318 K measures 90 mm bore × 190 mm OD × 64 mm width (3.543 × 7.48 × 2.52 in), mass about 8450 g. It is open, with no shields or seals.
How does the bore code in 2318 work?
The final two digits of 2318 are bore code 18, multiplied by 5 to give 90 mm.
What load can 2318-K take?
Catalogue values for 2318 K: dynamic C 151 kN, static C0 57 kN, fatigue limit Pu 2.5 kN. Use C in life calculation and C0 for static checks at 90 mm bore.
What is the speed rating of 2318-K?
SKF lists a 6300 r/min thermal reference speed and a 4500 r/min mechanical limiting speed for 2318 K; real limits also depend on lubrication and fits.
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.