32215T78-DB bearing: complete specifications & equivalents
The 32215T78-DB is a ISO 355 radial bearing sized 75 x 130 x 78 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 | 78 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 337 kN |
| Basic static load rating C0 | 425 kN |
| Fatigue load limit Pu | 49 kN |
| Reference speed (thermal) | 3200 rpm |
| Limiting speed (mechanical) | 5000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3700 g |
| Manufacturer designation | SKF 32215T78/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 | 3.071 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 |
|---|---|---|---|
| 32215T78 | 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 32215T78-DB model number is decoded
In the back-to-back (O) arrangement the load lines diverge toward the shaft axis, giving the pair a wide effective spread: 32215T78-DB resists overturning moments and tilting loads stiffly, which is why O-sets are preferred for gearbox output shafts and pinion supports. Selection arithmetic: the catalogue C 337 kN and C0 425 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 49 kN as the fatigue floor. Load system: C 337 kN against C0 425 kN gives a 1.26 balance, and 4.49 kN of dynamic capacity per millimetre of the 75 mm bore is the density figure to compare against neighbouring sizes. Setting note for 32215T78-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. Lubrication for the pair should be sized against the combined 78 mm width and 3700 g mass: two roller sets sweep twice the contact area of a single bearing of the same bore.For a 75 mm shaft carrying reversing axial load, SKF lists 32215T78-DB under catalogue execution SKF 32215T78/DB: a factory-matched back-to-back (O) matched pair tapered-roller pair, set and measured as one unit.Reading the designation: 32215T78 is the ISO 355 single-row base bearing (75 mm bore), and the suffix /DB marks the matched-set execution — arrangement, spacer grinding and factory clearance class. The pair envelope is 75×130×78 mm; the width covers both bearings of 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
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- roller large-end smearing against the cone rib after EP lubricant film failure
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- electrical pitting on VFD-driven shafts without grounding protection
- grease degradation after long shelf storage without rotation or re-greasing
Selection pitfalls — read before you substitute
- O and X arrangements are not interchangeable by turning the set around: 32215T78-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.
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 32215T78-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 32215T78-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- The 337/425 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 32215T78/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 32215T78-DB?
The SKF 32215T78/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 78 mm overall width (2.953 × 5.118 × 3.071 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 337 kN, C0 425 kN, fatigue load limit Pu 49 kN, reference speed 3,200 r/min, limiting speed 5,000 r/min, mass about 3.70 kg.
What does the /DB suffix on 32215T78-DB mean?
The base 32215T78 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 32215T78-DB for one bearing or the pair?
They are for the complete matched pair: C 337 kN dynamic and C0 425 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 32215T78 table values.
Can 32215T78-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.