30238T136-DB bearing: complete specifications & equivalents
The 30238T136-DB is a ISO 355 radial bearing sized 190 x 340 x 136 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 190 mm |
| Outer diameter D | 340 mm |
| Width B | 136 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 1308 kN |
| Basic static load rating C0 | 2000 kN |
| Fatigue load limit Pu | 190 kN |
| Reference speed (thermal) | 1100 rpm |
| Limiting speed (mechanical) | 1800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 44500 g |
| Manufacturer designation | SKF 30238T136/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 | 7.48 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 5.354 in |
| ISO bore code | 36 |
| Radial section height (D−d)/2 | 75 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) | 24 of 30 |
| Bore above smallest matched-db-series size | 155 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30238T136 | 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 30238T136-DB model number is decoded
On the SKF nameplate, 30238T136-DB reads as base 30238T136 in a /DB matched execution — the suffix is part of the order number because a matched set is ground for a specific axial clearance and cannot be assembled from loose single bearings. In the back-to-back (O) arrangement the load lines diverge toward the shaft axis, giving the pair a wide effective spread: 30238T136-DB resists overturning moments and tilting loads stiffly, which is why O-sets are preferred for gearbox output shafts and pinion supports. The C0/C balance of the pair is about 1.53; combined with the 190 kN fatigue limit this frames a set sized for reversing combined load on a 190 mm shaft rather than for pure radial duty. Dimensional interchange map: within its boundary plan the 190×340×136 mm envelope of 30238T136-DB is fixed, so shoulder, spacer and seal drawings can be dimensioned straight from the catalogue table. Setting note for 30238T136-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 136 mm width and 44500 g mass: two roller sets sweep twice the contact area of a single bearing of the same bore.The SKF 30238T136/DB is a 190×340×136 mm matched tapered-roller set — two single-row bearings in back-to-back (O) matched pair arrangement, ground and shipped together with the axial clearance fixed at the factory.
Typical equipment & failure modes
Common applications
- wind-turbine main shafts
- marine propulsion gearboxes
- large industrial mixer shafts
- large industrial mixer shafts
Known failure patterns
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- 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
- electrical pitting on VFD-driven shafts without grounding protection
- electrical pitting on VFD-driven shafts without grounding protection
Selection pitfalls — read before you substitute
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 30238T136-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Setting is built into 30238T136-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.
- Setting is built into 30238T136-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 1308/2000 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 30238T136/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 30238T136-DB?
The SKF 30238T136/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 190 mm bore, 340 mm outer diameter and 136 mm overall width (7.48 × 13.386 × 5.354 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 1308 kN, C0 2000 kN, fatigue load limit Pu 190 kN, reference speed 1,100 r/min, limiting speed 1,800 r/min, mass about 44.50 kg.
What does the /DB suffix on 30238T136-DB mean?
The base 30238T136 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 30238T136-DB for one bearing or the pair?
They are for the complete matched pair: C 1308 kN dynamic and C0 2000 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 30238T136 table values.
Can 30238T136-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 (m6 on a rotating 190 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 190 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.