31322T140X-DB bearing: complete specifications & equivalents
The 31322T140X-DB is a ISO 355 radial bearing sized 110 x 240 x 140 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 110 mm |
| Outer diameter D | 240 mm |
| Width B | 140 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 841 kN |
| Basic static load rating C0 | 1160 kN |
| Fatigue load limit Pu | 122 kN |
| Reference speed (thermal) | 1500 rpm |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 26000 g |
| Manufacturer designation | SKF 31322T140 X/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 | 4.331 in |
|---|---|
| Outer diameter D | 9.449 in |
| Width B | 5.512 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 65 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) | 16 of 30 |
| Bore above smallest matched-db-series size | 75 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 31322T140X | 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 31322T140X-DB model number is decoded
Thermal behaviour of the pair: heat generated in the 110 mm bore cones flows along the shaft and changes the setting; the /DB clearance class is chosen for the catalogue speed range 1,500–2,800 r/min, so re-select the clearance class if the application runs hotter. Do not separate 31322T140X-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 31322T140 X/DB is a 110×240×140 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.Reading the designation: 31322T140 X is the ISO 355 single-row base bearing (110 mm bore), and the suffix /DB marks the matched-set execution — arrangement, spacer grinding and factory clearance class. The pair envelope is 110×240×140 mm; the width covers both bearings of the set. 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 31322T140X-DB already accounts for the expected temperature gradient across the 140 mm pair width. With a pair mass of 26000 g across the 110×240×140 mm envelope, the set replaces what would otherwise be two separate bearings plus spacer grinding work — the factory setting is the engineering value being purchased. Journal and housing interface: the 110 mm bore takes a m6 shaft seat and the 240 mm outside diameter pairs with an H7 housing bore; the 140 mm width defines shoulder depth and the 26000 g mass is the dead load in thermal-growth calculations.
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
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- roller large-end smearing against the cone rib after EP lubricant film failure
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 31322T140X-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 31322T140X-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 31322T140X-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- The 841/1160 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 31322T140 X/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 31322T140X-DB?
The SKF 31322T140 X/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 110 mm bore, 240 mm outer diameter and 140 mm overall width (4.331 × 9.449 × 5.512 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 841 kN, C0 1160 kN, fatigue load limit Pu 122 kN, reference speed 1,500 r/min, limiting speed 2,800 r/min, mass about 26.00 kg.
What does the /DB suffix on 31322T140X-DB mean?
The base 31322T140 X 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 31322T140X-DB for one bearing or the pair?
They are for the complete matched pair: C 841 kN dynamic and C0 1160 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 31322T140 X table values.
Can 31322T140X-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 (m6 on a rotating 110 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 110 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.