30215T70-DB bearing: complete specifications & equivalents
The 30215T70-DB is a ISO 355 radial bearing sized 75 x 130 x 70 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 75 mm |
| Outer diameter D | 130 mm |
| Width B | 70 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 293 kN |
| Basic static load rating C0 | 355 kN |
| Fatigue load limit Pu | 41.5 kN |
| Reference speed (thermal) | 3400 rpm |
| Limiting speed (mechanical) | 5000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3200 g |
| Manufacturer designation | SKF 30215T70/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 | 2.953 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 2.756 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 27.5 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) | 9 of 30 |
| Bore above smallest matched-db-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30215T70 | 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 30215T70-DB model number is decoded
Selection arithmetic: the catalogue C 293 kN and C0 355 kN are ratings of the complete pair, not of one bearing — never halve them back to a single-row figure when checking L10 life, and use the pair Pu 41.5 kN as the fatigue floor. Material and manufacturing detail: the 3200 g catalogue mass reflects through-hardened bearing steel machined to the listed envelope; ring roundness and width tolerance keep the mounted-setting scatter inside the catalogue class. Setting note for 30215T70-DB: the axial clearance is set at the factory by selective spacer grinding for the /DB execution; in service, re-checking end play after the first thermal cycle catches seating relaxation before it becomes roller skid. Clamp the assembled pair axially through the cones — never through the rollers — and verify the 70 mm overall width against the catalogue value before final torquing of the shaft nut.For a 75 mm shaft carrying reversing axial load, SKF lists 30215T70-DB under catalogue execution SKF 30215T70/DB: a factory-matched back-to-back (O) matched pair tapered-roller pair, set and measured as one unit.Digit by digit, 30215T70-DB reads as the ISO 355 base bearing 30215T70 supplied as a back-to-back (O) matched pair matched pair (/DB); the 75 mm bore and 130 mm OD are per-bearing, the 70 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 30215T70-DB already accounts for the expected temperature gradient across the 70 mm pair width.
Typical equipment & failure modes
Common applications
- marine deck machinery shafts
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- construction machinery drives
Known failure patterns
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- 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
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- rib-roller contact scoring from loss of the EP additive film
Selection pitfalls — read before you substitute
- Clamp the 30215T70-DB pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 30215T70-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- O and X arrangements are not interchangeable by turning the set around: 30215T70-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 293/355 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 30215T70/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 30215T70-DB?
The SKF 30215T70/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 75 mm bore, 130 mm outer diameter and 70 mm overall width (2.953 × 5.118 × 2.756 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 293 kN, C0 355 kN, fatigue load limit Pu 41.5 kN, reference speed 3,400 r/min, limiting speed 5,000 r/min, mass about 3.20 kg.
What does the /DB suffix on 30215T70-DB mean?
The base 30215T70 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 30215T70-DB for one bearing or the pair?
They are for the complete matched pair: C 293 kN dynamic and C0 355 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 30215T70 table values.
Can 30215T70-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 75 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 75 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.