33111T88-DB bearing: complete specifications & equivalents
The 33111T88-DB is a ISO 355 radial bearing sized 55 x 95 x 88 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 55 mm |
| Outer diameter D | 95 mm |
| Width B | 88 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 232 kN |
| Basic static load rating C0 | 310 kN |
| Fatigue load limit Pu | 35.5 kN |
| Reference speed (thermal) | 4500 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2100 g |
| Manufacturer designation | SKF 33111T88/DB |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants |
| Last verified | 2026-09-29 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants) · extracted 2026-09-29
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants); 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 & matched-db-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 3.74 in |
| Width B | 3.465 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in matched-db-series | 35 mm |
| Largest outer diameter in matched-db-series | 480 mm |
| Width range across matched-db-series | 41.5–288 mm |
| Bore position in matched-db-series (smallest first) | 5 of 30 |
| Bore above smallest matched-db-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33111T88 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 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 33111T88-DB model number is decoded
Load sharing in 33111T88-DB depends on spacer face parallelism; a cocked spacer concentrates the reversing thrust on one bearing of the pair and shows up as asymmetric raceway wear at overhaul. The rotating cones of 33111T88-DB take a k5 seat on the 55 mm shaft; the cups are a transition-to-loose fit so the pair can be clamped to its factory setting during assembly.33111T88-DB (SKF 33111T88/DB) is the back-to-back (O) matched pair matched-set choice for a 55 mm shaft: a pair of tapered roller bearings whose combined envelope is 95×88 mm, delivered ready to mount with controlled internal clearance.On the SKF nameplate, 33111T88-DB reads as base 33111T88 in a /DB matched execution — the suffix is part of the order number because a matched set is ground for a specific axial clearance and cannot be assembled from loose single bearings. In the back-to-back (O) arrangement the load lines diverge toward the shaft axis, giving the pair a wide effective spread: 33111T88-DB resists overturning moments and tilting loads stiffly, which is why O-sets are preferred for gearbox output shafts and pinion supports. Catalogue mass 2100 g covers both bearings and the ground spacer of 33111T88-DB; keep the set complete — substituting one bearing or a non-ground spacer destroys the factory clearance. Dimensional interchange map: within its boundary plan the 55×95×88 mm envelope of 33111T88-DB is fixed, so shoulder, spacer and seal drawings can be dimensioned straight from the catalogue table.
Typical equipment & failure modes
Common applications
- industrial gearbox shafts and reducers
- differential and pinion drives
- pump and compressor shafts
- machine-tool spindles
Known failure patterns
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- electrical pitting on VFD-driven shafts without grounding protection
- brinelling from pressing the cone or cup home through the rollers
Selection pitfalls — read before you substitute
- Setting is built into 33111T88-DB; the classic field error is re-adjusting a matched pair as if it were two loose single bearings, which destroys the /DB clearance class.
- Setting is built into 33111T88-DB; the classic field error is re-adjusting a matched pair as if it were two loose single bearings, which destroys the /DB clearance class.
- Setting is built into 33111T88-DB; the classic field error is re-adjusting a matched pair as if it were two loose single bearings, which destroys the /DB clearance class.
- The 232/310 kN ratings are SKF catalogue 17000 values for this 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.
- Quote the full SKF 33111T88/DB designation when purchasing — base-number-only orders are ambiguous across executions and variants.
Frequently asked questions
What are the dimensions and catalogue data of 33111T88-DB?
The SKF 33111T88/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 55 mm bore, 95 mm outer diameter and 88 mm overall width (2.165 × 3.74 × 3.465 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 232 kN, C0 310 kN, fatigue load limit Pu 35.5 kN, reference speed 4,500 r/min, limiting speed 6,700 r/min, mass about 2.10 kg.
What does the /DB suffix on 33111T88-DB mean?
The base 33111T88 is the ISO 355 single-row bearing; the /DB suffix marks the matched-set execution — the arrangement (back-to-back (O)), the ground spacer and the factory-set axial clearance class. A matched set cannot be assembled from loose single bearings; quote the full designation when ordering.
Are the C and C0 ratings of 33111T88-DB for one bearing or the pair?
They are for the complete matched pair: C 232 kN dynamic and C0 310 kN static already include load sharing between the two bearings. Do not halve them for single-bearing checks, and do not compare them directly with the single-row 33111T88 table values.
Can 33111T88-DB be adjusted like two loose tapered bearings?
No — the axial clearance is set at the factory by selective spacer grinding. Mounting work is limited to clean seats, correct fits (k5 on a rotating 55 mm shaft) and axial clamping through the cones; re-setting in the field destroys the matched clearance class.
When should a back-to-back (O) matched set be chosen?
Choose the back-to-back (O) set where moment stiffness dominates — pinion supports, gearbox output shafts, crane sheaves. The diverging load lines give the widest effective spread at the 55 mm bore.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants on 2026-09-29. Read our editorial & correction policy.