31319-DF bearing: complete specifications & equivalents
The 31319-DF is a ISO 355 radial bearing sized 95 x 200 x 99 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 95 mm |
| Outer diameter D | 200 mm |
| Width B | 99 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 539 kN |
| Basic static load rating C0 | 710 kN |
| Fatigue load limit Pu | 78 kN |
| Reference speed (thermal) | 1800 rpm |
| Limiting speed (mechanical) | 3400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 13500 g |
| Manufacturer designation | SKF 31319/DF |
| 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-df-series range
| Bore d | 3.74 in |
|---|---|
| Outer diameter D | 7.874 in |
| Width B | 3.898 in |
| ISO bore code | 19 |
| Radial section height (D−d)/2 | 52.5 mm |
| Smallest bore in matched-df-series | 25 mm |
| Largest outer diameter in matched-df-series | 540 mm |
| Width range across matched-df-series | 34.5–280 mm |
| Bore position in matched-df-series (smallest first) | 15 of 35 |
| Bore above smallest matched-df-series size | 70 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 31319 | 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 31319-DF model number is decoded
In the face-to-face (X) arrangement the load lines of the two bearings converge toward the shaft axis: the set tolerates shaft deflection and thermal growth better than a back-to-back pair, but is less stiff against overturning moments. The 99 mm overall width of 31319-DF is the axial space the pair occupies. Dividing the pair C 539 kN by the 95 mm bore gives 5.67 kN per millimetre of journal for the complete arrangement — a density metric that compares matched sets across the face-to-face (X) matched pair family. Dimensional interchange map: within its boundary plan the 95×200×99 mm envelope of 31319-DF is fixed, so shoulder, spacer and seal drawings can be dimensioned straight from the catalogue table. Load sharing in 31319-DF 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 31319-DF take a k5 seat on the 95 mm shaft; the cups are a transition-to-loose fit so the pair can be clamped to its factory setting during assembly.For a 95 mm shaft carrying reversing axial load, SKF lists 31319-DF under catalogue execution SKF 31319/DF: a factory-matched face-to-face (X) matched pair tapered-roller pair, set and measured as one unit.Digit by digit, 31319-DF reads as the ISO 355 base bearing 31319 supplied as a face-to-face (X) matched pair matched pair (/DF); the 95 mm bore and 200 mm OD are per-bearing, the 99 mm width is for the set.
Typical equipment & failure modes
Common applications
- crane sheave and hoist gearboxes
- paper-machine and printing rolls
- construction machinery drives
- heavy industrial gearboxes and speed reducers
Known failure patterns
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- 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
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- hard-particle indentation of the tapered raceway in unfiltered oil
Selection pitfalls — read before you substitute
- Setting is built into 31319-DF; the classic field error is re-adjusting a matched pair as if it were two loose single bearings, which destroys the /DF clearance class.
- Setting is built into 31319-DF; the classic field error is re-adjusting a matched pair as if it were two loose single bearings, which destroys the /DF clearance class.
- Replace 31319-DF as a complete set: pairing a new bearing with a worn partner leaves the clearance undefined even when the designation matches.
- The 539/710 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 31319/DF designation when purchasing — base-number-only orders are ambiguous across executions and variants.
Frequently asked questions
What are the dimensions and catalogue data of 31319-DF?
The SKF 31319/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 95 mm bore, 200 mm outer diameter and 99 mm overall width (3.74 × 7.874 × 3.898 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 539 kN, C0 710 kN, fatigue load limit Pu 78 kN, reference speed 1,800 r/min, limiting speed 3,400 r/min, mass about 13.50 kg.
What does the /DF suffix on 31319-DF mean?
The base 31319 is the ISO 355 single-row bearing; the /DF suffix marks the matched-set execution — the arrangement (face-to-face (X)), 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 31319-DF for one bearing or the pair?
They are for the complete matched pair: C 539 kN dynamic and C0 710 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 31319 table values.
Can 31319-DF 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 95 mm shaft) and axial clamping through the cones; re-setting in the field destroys the matched clearance class.
When should a face-to-face (X) matched set be chosen?
Choose the face-to-face (X) set where the shaft grows thermally or alignment is imperfect — the converging load lines tolerate deflection. It is the default choice for wheel hubs and general gearbox shafts at the 95 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.