30314T84-DB bearing: complete specifications & equivalents
The 30314T84-DB is a ISO 355 radial bearing sized 70 x 150 x 84 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 70 mm |
| Outer diameter D | 150 mm |
| Width B | 84 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 465 kN |
| Basic static load rating C0 | 520 kN |
| Fatigue load limit Pu | 62 kN |
| Reference speed (thermal) | 3000 rpm |
| Limiting speed (mechanical) | 4500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6300 g |
| Manufacturer designation | SKF 30314T84/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 | 2.756 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 3.307 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 40 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) | 8 of 30 |
| Bore above smallest matched-db-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30314T84 | 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 30314T84-DB model number is decoded
Digit by digit, 30314T84-DB reads as the ISO 355 base bearing 30314T84 supplied as a back-to-back (O) matched pair matched pair (/DB); the 70 mm bore and 150 mm OD are per-bearing, the 84 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 30314T84-DB already accounts for the expected temperature gradient across the 84 mm pair width. Catalogue mass 6300 g covers both bearings and the ground spacer of 30314T84-DB; keep the set complete — substituting one bearing or a non-ground spacer destroys the factory clearance. Load system: C 465 kN against C0 520 kN gives a 1.12 balance, and 6.64 kN of dynamic capacity per millimetre of the 70 mm bore is the density figure to compare against neighbouring sizes. Inspection shorthand: at overhaul, mark both bearings and the spacer of 30314T84-DB before disassembly — the set is a matched system, and re-assembling with one component reversed changes the factory setting. Lubrication for the pair should be sized against the combined 84 mm width and 6300 g mass: two roller sets sweep twice the contact area of a single bearing of the same bore.SKF 30314T84/DB belongs to the SKF matched tapered-roller range — the 70 mm bore entry in back-to-back (O) matched pair arrangement, dimensioned 150 mm OD and 84 mm overall width for the pair.
Typical equipment & failure modes
Common applications
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
- paper-machine and printing rolls
- paper-machine and printing rolls
Known failure patterns
- false brinelling on idle paired sets exposed to machine vibration
- false brinelling on idle paired sets exposed to machine vibration
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- brinelling from pressing the cone or cup home through the rollers
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Setting is built into 30314T84-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.
- Clamp the 30314T84-DB pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Setting is built into 30314T84-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.
- The 465/520 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 30314T84/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 30314T84-DB?
The SKF 30314T84/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 70 mm bore, 150 mm outer diameter and 84 mm overall width (2.756 × 5.906 × 3.307 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 465 kN, C0 520 kN, fatigue load limit Pu 62 kN, reference speed 3,000 r/min, limiting speed 4,500 r/min, mass about 6.30 kg.
What does the /DB suffix on 30314T84-DB mean?
The base 30314T84 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 30314T84-DB for one bearing or the pair?
They are for the complete matched pair: C 465 kN dynamic and C0 520 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 30314T84 table values.
Can 30314T84-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 70 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 70 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.