33220 bearing: complete specifications & equivalents
The 33220 is a ISO 355 radial bearing sized 100 x 180 x 63 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 100 mm |
| Outer diameter D | 180 mm |
| Width B | 63 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 532 kN |
| Basic static load rating C0 | 655 kN |
| Fatigue load limit Pu | 71 kN |
| Reference speed (thermal) | 2600 rpm |
| Limiting speed (mechanical) | 3600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6750 g |
| Manufacturer designation | SKF 33220 |
| 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 & 33200-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 7.087 in |
| Width B | 2.48 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 40 mm |
| Smallest bore in 33200-series | 25 mm |
| Largest outer diameter in 33200-series | 180 mm |
| Width range across 33200-series | 22–63 mm |
| Bore position in 33200-series (smallest first) | 18 of 18 |
| Bore above smallest 33200-series size | 75 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33220 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 355 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 33220 model number is decoded
33220 is a single-row tapered roller bearing in the ISO 33200 dimension series: a separable cone-and-cup design for combined radial and one-direction axial load, listed by SKF in SKF catalogue PUB BU/P1 17000.The code breaks down as type prefix 3 (tapered roller), series 32 (the medium wide section), and bore code 20 = 100 mm; dimensions 100×180×63 mm therefore match the ISO 355 envelope. In SKF suffix language a bare 33220 is the standard execution; B marks a larger contact angle and Q or J2 mark clearance/cage variants, all quoted separately. At 2,600 r/min reference speed the 40.0 mm-section 33220 is governed thermally by preload and lubricant flow; grease or oil selection should be made against that value, with 3,600 r/min as the mechanical ceiling. A single 33220 locates the shaft in one axial direction only; mount it against a second bearing in O (back-to-back) or X (face-to-face) arrangement, and set the running clearance by the mounting procedure — not by feel.
Typical equipment & failure modes
Common applications
- marine deck machinery shafts
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- rolling-mill auxiliary 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
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- brinelling from pressing the cone or cup home through the rollers
Selection pitfalls — read before you substitute
- Mount the 100 mm bore 33220 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 332 series at 100 mm bore (180×63 mm) is the wide medium-section choice — more capacity than 30220 in the same OD class but a wider footprint; re-check housing width and pair setting before substituting.
- At the 532 kN rating of 33220, 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.
- Setting is a design value, not an assembly feel: excessive preload in the 33220 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- Shaft and housing fillets must clear the bearing chamfer so the 63 mm-wide cup seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
- The 532/655 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 33220 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 33220 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 33220?
The SKF 33220 is a single-row tapered roller bearing with 100 mm bore, 180 mm outer diameter and 63 mm width (3.937 × 7.087 × 2.48 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 532 kN, C0 655 kN, fatigue load limit Pu 71 kN, reference speed 2,600 r/min, limiting speed 3,600 r/min, mass about 6750 g. It is an open, separable bearing with a pressed-steel cage.
How does the 33220 bore code work?
The last two digits of 33220 are bore code 20, so 20 × 5 = 100 mm bore. The 180 mm OD and 63 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 33220 series and basic execution designations mean?
The leading 3 marks a single-row tapered roller bearing; the second digit 32 is the ISO 355 series (medium wide 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 33220 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 33220 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 33220 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.