33012 bearing: complete specifications & equivalents
The 33012 is a ISO 355 radial bearing sized 60 x 95 x 27 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 60 mm |
| Outer diameter D | 95 mm |
| Width B | 27 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 113 kN |
| Basic static load rating C0 | 143 kN |
| Fatigue load limit Pu | 16 kN |
| Reference speed (thermal) | 5300 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 700 g |
| Manufacturer designation | SKF 33012 |
| 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 & 33000-series range
| Bore d | 2.362 in |
|---|---|
| Outer diameter D | 3.74 in |
| Width B | 1.063 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 17.5 mm |
| Smallest bore in 33000-series | 50 mm |
| Largest outer diameter in 33000-series | 225 mm |
| Width range across 33000-series | 24–59 mm |
| Bore position in 33000-series (smallest first) | 3 of 16 |
| Bore above smallest 33000-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33012 | 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 33012 model number is decoded
In SKF catalogue PUB BU/P1 17000, 33012 appears as SKF 33012: an open, single-row tapered roller bearing in the slim light section of the 33000 dimension series, supplied with a pressed-steel cage as standard.Digit by digit, 33012 reads as bearing type 3 (single-row tapered roller), slim light section series 30, and bore reference 12 resolving to 60 mm; 95 mm OD and 27 mm width are the matching ISO 355 boundary values. The SKF catalogue adds the ISO 355 dimension-series code after the bare number (e.g. 2CE); it is the dimensional series, not a separate part number. The 16 kN Pu figure feeds the adjusted-life equation at contaminated or partial-film conditions, and the 1.27 C0/C balance shows this execution is tuned to thrust-heavy combined loads rather than pure radial running. Fit selection follows the rotating ring — interference on a rotating cone — and two 33012 units are required to take reversing thrust; keep the induced axial load inside the rated capacity when calculating the pair.
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
- false brinelling on idle paired sets exposed to machine vibration
- roller large-end smearing against the cone rib after EP lubricant film failure
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- rib-roller contact scoring from loss of the EP additive film
Selection pitfalls — read before you substitute
- Mount the 60 mm bore 33012 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 330 series at 60 mm bore (95×27 mm) is the slim-OD envelope: it buys radial space but gives up capacity against a 30212 of the same bore — confirm the L10 margin before downsizing into it.
- A single 33012 cannot locate the shaft axially in both directions; mounting it singly on a reversing-thrust shaft leaves one direction uncontrolled — always use an O or X matched pair for bidirectional location.
- Do not mix brands or executions inside one 33012 pair — matched sets are ground for a specific setting, and pairing a SKF basic unit with a different suffix variant will not share the setting evenly.
- Shaft and housing fillets must clear the bearing chamfer so the 27 mm-wide cup seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
- The 113/143 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 33012 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 33012 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 33012?
The SKF 33012 is a single-row tapered roller bearing with 60 mm bore, 95 mm outer diameter and 27 mm width (2.362 × 3.74 × 1.063 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 113 kN, C0 143 kN, fatigue load limit Pu 16 kN, reference speed 5,300 r/min, limiting speed 6,700 r/min, mass about 700 g. It is an open, separable bearing with a pressed-steel cage.
How does the 33012 bore code work?
The last two digits of 33012 are bore code 12, so 12 × 5 = 60 mm bore. The 95 mm OD and 27 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 33012 series and basic execution designations mean?
The leading 3 marks a single-row tapered roller bearing; the second digit 30 is the ISO 355 series (slim light 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 33012 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 33012 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 33012 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.