30218 bearing: complete specifications & equivalents
The 30218 is a ISO 355 radial bearing sized 90 x 160 x 32.5 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 | 160 mm |
| Width B | 32.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 240 kN |
| Basic static load rating C0 | 245 kN |
| Fatigue load limit Pu | 28.5 kN |
| Reference speed (thermal) | 3400 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2500 g |
| Manufacturer designation | SKF 30218 |
| 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 & 30200-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.28 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 30200-series | 15 mm |
| Largest outer diameter in 30200-series | 580 mm |
| Width range across 30200-series | 11.75–104 mm |
| Bore position in 30200-series (smallest first) | 18 of 37 |
| Bore above smallest 30200-series size | 75 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30218 | 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 30218 model number is decoded
For a 90 mm shaft carrying combined load, SKF lists 30218 under catalogue execution SKF 30218: one open single-row tapered roller bearing in the standard section of the 30200 family.Digit by digit, 30218 reads as bearing type 3 (single-row tapered roller), standard section series 0, and bore reference 18 resolving to 90 mm; 160 mm OD and 32.5 mm width are the matching ISO 355 boundary values. 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 35.0 mm radial section height ((160−90)/2) and 2500 g catalogue mass frame a 90 mm bore bearing rated at 240 kN C — roughly 2.67 kN of dynamic capacity per millimetre of bore before application factors. Note the minimum-axial-load requirement: at light radial load and high speed the rollers of 30218 must still be held into the rib contact, which is another reason the catalogue recommends paired mounting with controlled setting.
Typical equipment & failure modes
Common applications
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
- paper-machine and printing rolls
- construction machinery drives
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
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Mount the 90 mm bore 30218 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 302 series at 90 mm bore (160×32.5 mm) is the standard tapered-roller envelope; stepping to a 32218 or 32318 changes OD, width and heat generation — it is not a drop-in swap when the housing and speed are fixed.
- When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 30218 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- The tapered contact angle creates an induced axial load under pure radial force; include it in the 30218 rating calculation (and account for it in both bearings of a pair) or the unloaded bearing skids its rollers.
- The 30218 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 240/245 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 30218 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 30218 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 30218?
The SKF 30218 is a single-row tapered roller bearing with 90 mm bore, 160 mm outer diameter and 32.5 mm width (3.543 × 6.299 × 1.28 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 240 kN, C0 245 kN, fatigue load limit Pu 28.5 kN, reference speed 3,400 r/min, limiting speed 4,000 r/min, mass about 2500 g. It is an open, separable bearing with a pressed-steel cage.
How does the 30218 bore code work?
The last two digits of 30218 are bore code 18, so 18 × 5 = 90 mm bore. The 160 mm OD and 32.5 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 30218 series and basic execution designations mean?
The leading 3 marks a single-row tapered roller bearing; the second digit 0 is the ISO 355 series (standard 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 30218 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 30218 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 30218 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.