33020T88-DB bearing: complete specifications & equivalents
The 33020T88-DB is a ISO 355 radial bearing sized 100 x 150 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 | 100 mm |
| Outer diameter D | 150 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 | 477 kN |
| Basic static load rating C0 | 765 kN |
| Fatigue load limit Pu | 83 kN |
| Reference speed (thermal) | 2800 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 5000 g |
| Manufacturer designation | SKF 33020T88/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 | 3.937 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 3.465 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25 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) | 14 of 30 |
| Bore above smallest matched-db-series size | 65 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33020T88 | 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 33020T88-DB model number is decoded
Back-to-back matching puts the large rib ends outward — the stiffest arrangement for moment load, but one that converts shaft thermal growth into preload change; the factory setting of 33020T88-DB already accounts for the expected temperature gradient across the 88 mm pair width. Dividing the pair C 477 kN by the 100 mm bore gives 4.77 kN per millimetre of journal for the complete arrangement — a density metric that compares matched sets across the back-to-back (O) matched pair family. Cross-section geometry: the 25.0 mm half-section ((150−100)/2) places the roller pitch diameter near 125 mm, and the 88 mm axial width sets the abutment depth — geometry that fixes the contact angle behaviour of 33020T88-DB. Spacer discipline: the spacer between the two bearings of 33020T88-DB is ground to the individual set — it carries a serial link to the pair, so never swap spacers between sets of the same designation. Do not separate 33020T88-DB into single-bearing service stock — as individual bearings the components are not interchangeable with catalogue single-row executions because the rings are ground for the set.The SKF 33020T88/DB is a 100×150×88 mm matched tapered-roller set — two single-row bearings in back-to-back (O) matched pair arrangement, ground and shipped together with the axial clearance fixed at the factory.The code breaks down as base bearing 33020T88 plus matched-set suffix /DB: two bearings of the 100 mm bore size, paired back-to-back (O) matched pair, with the 88 mm overall width spanning the whole arrangement.
Typical equipment & failure modes
Common applications
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
- construction machinery drives
Known failure patterns
- roller large-end smearing against the cone rib after EP lubricant film failure
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- rib-roller contact scoring from loss of the EP additive film
- brinelling from pressing the cone or cup home through the rollers
Selection pitfalls — read before you substitute
- Replace 33020T88-DB as a complete set: pairing a new bearing with a worn partner leaves the clearance undefined even when the designation matches.
- Clamp the 33020T88-DB pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- O and X arrangements are not interchangeable by turning the set around: 33020T88-DB in back-to-back (O) matched pair arrangement has its load-line geometry fixed — specify the arrangement from the shaft thermal and stiffness analysis.
- The 477/765 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 33020T88/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 33020T88-DB?
The SKF 33020T88/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 100 mm bore, 150 mm outer diameter and 88 mm overall width (3.937 × 5.906 × 3.465 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 477 kN, C0 765 kN, fatigue load limit Pu 83 kN, reference speed 2,800 r/min, limiting speed 4,000 r/min, mass about 5.00 kg.
What does the /DB suffix on 33020T88-DB mean?
The base 33020T88 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 33020T88-DB for one bearing or the pair?
They are for the complete matched pair: C 477 kN dynamic and C0 765 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 33020T88 table values.
Can 33020T88-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 100 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 100 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.