32318 bearing: complete specifications & equivalents
The 32318 is a ISO 355 radial bearing sized 90 x 190 x 67.5 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 | 67.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 487 kN |
| Basic static load rating C0 | 610 kN |
| Fatigue load limit Pu | 65.5 kN |
| Reference speed (thermal) | 2600 rpm |
| Limiting speed (mechanical) | 3600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 8400 g |
| Manufacturer designation | SKF 32318 |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB); 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 & 32300-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 7.48 in |
| Width B | 2.657 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 50 mm |
| Smallest bore in 32300-series | 20 mm |
| Largest outer diameter in 32300-series | 460 mm |
| Width range across 32300-series | 22.25–154 mm |
| Bore position in 32300-series (smallest first) | 16 of 30 |
| Bore above smallest 32300-series size | 70 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32318 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the 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 32318 model number is decoded
In SKF catalogue PUB BU/P1 17000, 32318 appears as SKF 32318: an open, single-row tapered roller bearing in the extra-heavy section of the 32300 dimension series, supplied with a pressed-steel cage as standard.The code breaks down as type prefix 3 (tapered roller), series 2 (the extra-heavy section), and bore code 18 = 90 mm; dimensions 90×190×67.5 mm therefore match the ISO 355 envelope. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. The 65.5 kN Pu figure feeds the adjusted-life equation at contaminated or partial-film conditions, and the 1.25 C0/C balance shows this execution is tuned to thrust-heavy combined loads rather than pure radial running. Specify pairs rather than single units wherever thrust reverses: the tapered contact of 32318 generates an induced axial load under radial force, and an unpaired bearing on a reversing shaft will run slack and fret its seat.
Typical equipment & failure modes
Common applications
- construction machinery drives
- marine deck machinery shafts
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
Known failure patterns
- cup or cone misalignment when the separable rings are not seated square during mounting
- loose cup rotation in the housing when the specified press fit is not achieved
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- grease degradation after long shelf storage without rotation or re-greasing
Selection pitfalls — read before you substitute
- Mount the 90 mm bore 32318 by induction heating of the cone (max 120 °C — the pressed-steel cage sets the ceiling, not the steel); driving it home through the cup or rollers brinells the tapered raceway.
- The 323 series at 90 mm bore (190×67.5 mm) is the heavy-duty section of the tapered family; it runs hotter at the same speed than a 30218, so recalculate dn and lubricant film before substitution.
- At the 487 kN rating of 32318, preload class changes stiffness by tens of percent but also heat generation; select light preload for the 3,600 r/min speed end and heavier preload only where moment stiffness dominates.
- At the 487 kN rating of 32318, preload class changes stiffness by tens of percent but also heat generation; select light preload for the 3,600 r/min speed end and heavier preload only where moment stiffness dominates.
- The 32318 shares its ISO 355 envelope with other tapered bearings of the same code but is not a drop-in replacement for a ball bearing: it cannot run effectively under pure radial load without a minimum axial load, and a deep-groove bearing cannot replace its combined-load duty.
- The 487/610 kN ratings are SKF catalogue 17000 values for the basic execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of 32318 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 32318 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 32318?
The SKF 32318 is a single-row tapered roller bearing with 90 mm bore, 190 mm outer diameter and 67.5 mm width (3.543 × 7.48 × 2.657 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 487 kN, C0 610 kN, fatigue load limit Pu 65.5 kN, reference speed 2,600 r/min, limiting speed 3,600 r/min, mass about 8400 g. It is an open, separable bearing with a pressed-steel cage.
How does the 32318 bore code work?
The last two digits of 32318 are bore code 18, so 18 × 5 = 90 mm bore. The 190 mm OD and 67.5 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 32318 series and basic execution designations mean?
The leading 3 marks a single-row tapered roller bearing; the second digit 2 is the ISO 355 series (extra-heavy section). The SKF catalogue lists the ISO 355 dimension-series code after the bare number. A steeper-contact-angle variant (B suffix) is a different order number and is not interchangeable with the basic execution.
Can a single 32318 take axial load in both directions?
No — one single-row tapered roller bearing reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair: O (back-to-back) for a rigid, moment-resisting arrangement, X (face-to-face) where thermal expansion must be tolerated, or tandem where one-direction thrust is shared.
How does 32318 compare with a ball bearing of the same bore?
A tapered roller bearing has line contact and a steep contact angle: much higher combined axial-plus-radial capacity and shock resistance than a ball bearing of the same bore, at the cost of speed, one-direction thrust, mandatory pairing for reversing loads and a minimum axial load requirement. A ball bearing cannot be dropped into a combined-load 32318 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB on 2026-09-26. Read our editorial & correction policy.