3310-ATN9 bearing: complete specifications & equivalents
The 3310-ATN9 is a ISO 15 radial bearing sized 50 x 110 x 44.4 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 50 mm |
| Outer diameter D | 110 mm |
| Width B | 44.4 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 90 kN |
| Basic static load rating C0 | 64 kN |
| Fatigue load limit Pu | 2.75 kN |
| Reference speed (thermal) | 6700 rpm |
| Limiting speed (mechanical) | 6000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1700 g |
| Manufacturer designation | 3310 ATN9 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); 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 & 3300-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 1.748 in |
| ISO bore code | 10 |
| Radial section height (D−d)/2 | 30 mm |
| Smallest bore in 3300-series | 15 mm |
| Largest outer diameter in 3300-series | 240 mm |
| Width range across 3300-series | 19–92.1 mm |
| Bore position in 3300-series (smallest first) | 9 of 20 |
| Bore above smallest 3300-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 3310-DNRCBM | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 50×110×44.4 mm envelope with catalogue ratings within 10 %; 3310 DNRCBM is the brass cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 3310-A | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 50×110×44.4 mm envelope with catalogue ratings within 10 %; 3310 A is the stamped steel cage, open arrangement execution of this size — boundary dimensions interchangeable, execution differs. |
| 3310-DMA | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×44.4 mm envelope, but catalogue C/C0 differ between executions (90/64 kN vs 93.6/85 kN) — boundary dimensions match, not a load-rating equivalent. |
| 3310-A-2Z | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 50×110×44.4 mm envelope with catalogue ratings within 10 %; 3310 A-2Z is the stamped steel cage, shields (-2Z) execution of this size — boundary dimensions interchangeable, execution differs. |
| 3310-A-2RS1 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 50×110×44.4 mm envelope with catalogue ratings within 10 %; 3310 A-2RS1 is the stamped steel cage, contact NBR seals (-2RS1) execution of this size — boundary dimensions interchangeable, execution differs. |
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 3310-ATN9 model number is decoded
3310 ATN9 is SKF's 50 mm-bore double-row angular-contact ball bearing of the 3300 series — two ball rows back-to-back for two-direction axial location in one unit, 50×110×44.4 mm. A on a double-row bearing means no filling slots, so both rows carry their full ball complement in both directions. glass-fibre reinforced PA66 cage, ball-centred (suffix TN9), with a 120 °C continuous-temperature ceiling. Envelope 50×110×44.4 mm (1.969×4.331×1.748 in), 30.0 mm radial section height, C 90 kN, C0 64 kN, Pu 2.75 kN.reference speed 6,700 r/min (thermal) and limiting speed 6,000 r/min (mechanical), catalogue mass 1700 g. Load balance: C0 64 kN against C 90 kN gives a 0.71 ratio, typical of a double-row bidirectional design; Pu 2.75 kN enters the SKF adjusted-life equation rather than the basic rating life. Sizing arithmetic on the 50 mm bore: 90 kN C divided by the 30.0 mm radial section height gives 3.0 kN per section millimetre; the 1700 g mass and 3 % Pu/C share frame the light-load floor for the adjusted-life check. Bore-to-OD planning: OD 110 over bore 50 is a 2.20× step for this size, and the 44.4 mm width gives a bore/width ratio of 1.13; use these ratios when housing space around the 50 mm shaft is the first constraint.
Typical equipment & failure modes
Common applications
- printing and converting machinery
- gearbox input and output shafts with bidirectional thrust
- two-direction thrust positions without room for a paired single-row set
Known failure patterns
- tilted mounting that loads one double row more heavily than the other
- false brinelling on the loaded row while the shaft stands idle under vibration
- TN9 cage embrittlement in a hot gearbox position beyond the 120 °C polymer ceiling
- electrical pitting on VFD-driven shafts without grounding protection
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- The double-row 3310 takes thrust in both directions by itself — that is the reason to choose it over two single-row bearings: one housing bore, one fit, built-in set geometry.
- Compared with a single-row pair of the same bore, the double-row 3310 occupies less axial space but offers less freedom to adjust preload — do not substitute without re-checking the arrangement.
- Compared with a single-row pair of the same bore, the double-row 3310 occupies less axial space but offers less freedom to adjust preload — do not substitute without re-checking the arrangement.
- A capped 3310-2Z/-2RS1 execution of this envelope exists for sealed-for-life duty; an open double-row bearing needs application sealing and a defined lubricant supply.
- Catalogue ratings are SKF PUB BU/P1 17000 figures for 3310 ATN9 as the double atn9 execution; the other order numbers of the 3310 size are different products and may carry different ratings — always quote the full designation when purchasing.
Frequently asked questions
What are the dimensions and catalogue data of 3310-ATN9?
3310 ATN9 measures 50 mm bore × 110 mm OD × 44.4 mm width (1.969 × 4.331 × 1.748 in), mass about 1700 g. SKF 17000 ratings: C 90 kN, C0 64 kN, Pu 2.75 kN, reference speed 6,700 r/min (thermal) and limiting speed 6,000 r/min (mechanical).
What does the ATN9 suffix mean?
A on a double-row bearing means no filling slots, so both rows carry their full ball complement in both directions. glass-fibre reinforced PA66 cage, ball-centred (suffix TN9), with a 120 °C continuous-temperature ceiling.
Why choose the double-row 3310 instead of two single-row bearings?
The double-row bearing locates the shaft in both axial directions in one unit, in one housing bore and with factory-controlled axial clearance — a more compact arrangement than a pair, with no field matching of ground faces. A single-row pair offers adjustable preload instead.
What does the D mean in ATN9?
D marks a two-piece inner ring, used on the heavy 33-series executions to simplify mounting; the rest of the suffix identifies the cage (MA brass outer-ring-centred, M brass ball-centred, J1 stamped steel, TN9 PA66) and snap-ring/clearance options (NR, CB).
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.