31316-DF bearing: complete specifications & equivalents
The 31316-DF is a ISO 355 radial bearing sized 80 x 170 x 85 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 80 mm |
| Outer diameter D | 170 mm |
| Width B | 85 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 473 kN |
| Basic static load rating C0 | 530 kN |
| Fatigue load limit Pu | 61 kN |
| Reference speed (thermal) | 2400 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 8650 g |
| Manufacturer designation | SKF 31316/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 | 3.15 in |
|---|---|
| Outer diameter D | 6.693 in |
| Width B | 3.346 in |
| ISO bore code | 16 |
| Radial section height (D−d)/2 | 45 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) | 12 of 35 |
| Bore above smallest matched-df-series size | 55 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 31316 | 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 31316-DF model number is decoded
Reading the designation: 31316 is the ISO 355 single-row base bearing (80 mm bore), and the suffix /DF marks the matched-set execution — arrangement, spacer grinding and factory clearance class. The pair envelope is 80×170×85 mm; the width covers both bearings of the set. 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 85 mm overall width of 31316-DF is the axial space the pair occupies. With a pair mass of 8650 g across the 80×170×85 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. Dimensional interchange map: within its boundary plan the 80×170×85 mm envelope of 31316-DF is fixed, so shoulder, spacer and seal drawings can be dimensioned straight from the catalogue table. Spacer discipline: the spacer between the two bearings of 31316-DF is ground to the individual set — it carries a serial link to the pair, so never swap spacers between sets of the same designation. Clamp the assembled pair axially through the cones — never through the rollers — and verify the 85 mm overall width against the catalogue value before final torquing of the shaft nut.Ordering number SKF 31316/DF in SKF catalogue PUB BU/P1 17000 denotes two single-row tapered roller bearings supplied as a matched face-to-face (X) matched pair set for a 80 mm shaft — one order number, one factory setting.
Typical equipment & failure modes
Common applications
- paper-machine and printing rolls
- construction machinery drives
- marine deck machinery shafts
- marine deck machinery shafts
Known failure patterns
- false brinelling on idle paired sets exposed to machine vibration
- 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
- grease degradation after long shelf storage without rotation or re-greasing
- hard-particle indentation of the tapered raceway in unfiltered oil
Selection pitfalls — read before you substitute
- A matched /DF set is ground as one system: never separate the two bearings of 31316-DF or swap the spacer — the factory clearance is lost the moment the set is broken.
- Clamp the 31316-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Clamp the 31316-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- The 473/530 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 31316/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 31316-DF?
The SKF 31316/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 80 mm bore, 170 mm outer diameter and 85 mm overall width (3.15 × 6.693 × 3.346 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 473 kN, C0 530 kN, fatigue load limit Pu 61 kN, reference speed 2,400 r/min, limiting speed 4,000 r/min, mass about 8.65 kg.
What does the /DF suffix on 31316-DF mean?
The base 31316 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 31316-DF for one bearing or the pair?
They are for the complete matched pair: C 473 kN dynamic and C0 530 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 31316 table values.
Can 31316-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 80 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 80 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.