331606A bearing: complete specifications & equivalents
The 331606A is a ANSI ABMA 19.2 radial bearing sized 371.475 x 501.65 x 155.575 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 371.475 mm |
| Outer diameter D | 501.65 mm |
| Width B | 155.575 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 1976 kN |
| Basic static load rating C0 | 4250 kN |
| Fatigue load limit Pu | 345 kN |
| Operating temperature | -40 to +120 °C |
| Mass | 76500 g |
| Manufacturer designation | SKF 331606 A |
| Standard | ANSI ABMA 19.2 |
| 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 & tdo-series range
| Bore d | 14.625 in |
|---|---|
| Outer diameter D | 19.75 in |
| Width B | 6.125 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 65.1 mm |
| Smallest bore in tdo-series | 101.6 mm |
| Largest outer diameter in tdo-series | 596.9 mm |
| Width range across tdo-series | 49.212–284 mm |
| Bore position in tdo-series (smallest first) | 18 of 23 |
| Bore above smallest tdo-series size | 269.875 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 331606A | 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 331606A model number is decoded
Static check: with C0 4250 kN the unit carries shock and standstill load up to the static safety factor of the application; the 345 kN Pu governs the fatigue side of the same calculation. Dimensional interchange map: within its boundary plan the 371.475×501.65×155.575 mm envelope of 331606A is fixed, so shoulder, spacer and seal drawings can be dimensioned straight from the catalogue table. The TDO/XDC execution of 331606A differs from sibling variants in internal detail — spacer style, rib execution or clearance class — while sharing the 371.475×501.65×155.575 mm boundary; the full designation including the variant is the only safe order reference. In the TDO X-arrangement the two cones of 331606A locate the shaft in both axial directions; the housing seat for the 501.65 mm double cup is a loose-to-transition fit so thermal growth does not preload the rows.In SKF catalogue PUB BU/P1 17000, 331606A appears as SKF 331606 A: a TDO-design double-row tapered roller bearing for a 371.475 mm shaft, rated C 1976 kN with the factory-set internal clearance of the TDO/XDC variant.The code SKF 331606 A is not an ISO 355 number: double-row tapered bearings of this size follow SKF works numbering, where 331606 fixes the 371.475×501.65×155.575 mm envelope and the variant suffix (TDO/XDC) fixes the internal execution. At 76.5 kg the 331606A assembly needs mechanical handling at mounting — sling through the bore or use lifting eyes on the shaft, and never lift the unit by one ring alone: the rings are separable.
Typical equipment & failure modes
Common applications
- offshore winch and drawworks drums
- rolling-mill roll-neck bearings
- heavy-duty rolling-mill gearboxes
- large industrial mixer shafts
Known failure patterns
- water or scale ingress at the separable ring parting lines in roll-neck service
- thermal clearance loss when housing cooling is undersized for two rows of tapered contact
- 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
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Contamination control matters twice over for double-row units: particles trapped between the rows of 331606A cannot migrate out, so flush the housing before assembly and fit filtration matched to the oil flow.
- The 371.475 mm bore seat must be checked for ovality before mounting — at this size a worn seat lets the cone creep, and fretting debris then works between the rows of 331606A.
- Lifting 331606A by one ring separates the assembly; sling through the 371.475 mm bore or use the shaft as the lifting member.
- The 1976/4250 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 331606 A designation when purchasing — base-number-only orders are ambiguous across executions and variants.
Frequently asked questions
What are the dimensions and catalogue data of 331606A?
The SKF 331606 A is a double-row tapered roller bearing of TDO design with 371.475 mm bore, 501.65 mm outer diameter and 155.575 mm overall width (14.625 × 19.75 × 6.125 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 1976 kN, C0 4250 kN, fatigue load limit Pu 345 kN, mass about 76.50 kg.
What does the TDO/XDC variant code on 331606A mean?
Double-row tapered bearings of this size follow SKF works numbering: the base number 331606 fixes the 371.475×501.65×155.575 mm envelope, and the TDO/XDC code identifies the internal design variant — spacer execution, rib detail and clearance class. Same-envelope units under a different variant are not interchangeable without checking the variant meaning.
Why does the catalogue list no speed rating for 331606A?
Bearings of this size class run in slow, heavily loaded machinery where the permissible speed is set by the application heat balance rather than a universal table value. Plan lubrication and cooling against the 76.5 kg assembly mass and instrument the first run with temperature logging.
Can components of 331606A be interchanged with another unit of the same base number?
No — cones, cups and spacers of a double-row set are matched per serial and the clearance is set by selective grinding at the factory. Replace 331606A as a complete assembly in the same TDO/XDC variant.
How does 331606A react axial load?
The TDO design works as a fixed X arrangement: one double cup with two cones locates the shaft in both axial directions, with load shared between the two rows according to the factory-set clearance.
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.