31317T133-19-DB bearing: complete specifications & equivalents
The 31317T133-19-DB is a ISO 355 radial bearing sized 85 x 180 x 133.19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 85 mm |
| Outer diameter D | 180 mm |
| Width B | 133.19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 510 kN |
| Basic static load rating C0 | 570 kN |
| Fatigue load limit Pu | 64 kN |
| Reference speed (thermal) | 2200 rpm |
| Limiting speed (mechanical) | 3800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12000 g |
| Manufacturer designation | SKF 31317T133.19/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 | 3.346 in |
|---|---|
| Outer diameter D | 7.087 in |
| Width B | 5.244 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 47.5 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) | 11 of 30 |
| Bore above smallest matched-db-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 31317T133 | 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 31317T133-19-DB model number is decoded
When a matched /DB set like 31317T133-19-DB is replaced, replace the whole set: mixing a new bearing with a worn partner from the old set leaves the clearance and load sharing of the pair undefined. Clamp the assembled pair axially through the cones — never through the rollers — and verify the 133.19 mm overall width against the catalogue value before final torquing of the shaft nut.The SKF 31317T133.19/DB is a 85×180×133.19 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.Digit by digit, 31317T133-19-DB reads as the ISO 355 base bearing 31317T133.19 supplied as a back-to-back (O) matched pair matched pair (/DB); the 85 mm bore and 180 mm OD are per-bearing, the 133.19 mm width is for 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 31317T133-19-DB already accounts for the expected temperature gradient across the 133.19 mm pair width. Dividing the pair C 510 kN by the 85 mm bore gives 6.00 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. Assembly datum check: verify the 133.19 mm width against the drawing before clamping — the width is the assembled result and the quickest field check that the correct execution of 31317T133-19-DB is on the shaft.
Typical equipment & failure modes
Common applications
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
Known failure patterns
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- rib-roller contact scoring from loss of the EP additive film
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Replace 31317T133-19-DB as a complete set: pairing a new bearing with a worn partner leaves the clearance undefined even when the designation matches.
- Setting is built into 31317T133-19-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.
- O and X arrangements are not interchangeable by turning the set around: 31317T133-19-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 510/570 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 31317T133.19/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 31317T133-19-DB?
The SKF 31317T133.19/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 85 mm bore, 180 mm outer diameter and 133.19 mm overall width (3.346 × 7.087 × 5.244 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 510 kN, C0 570 kN, fatigue load limit Pu 64 kN, reference speed 2,200 r/min, limiting speed 3,800 r/min, mass about 12.00 kg.
What does the /DB suffix on 31317T133-19-DB mean?
The base 31317T133.19 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 31317T133-19-DB for one bearing or the pair?
They are for the complete matched pair: C 510 kN dynamic and C0 570 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 31317T133.19 table values.
Can 31317T133-19-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 85 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 85 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.