3303-ATN9 bearing: complete specifications & equivalents
The 3303-ATN9 is a ISO 15 radial bearing sized 17 x 47 x 22.2 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 17 mm |
| Outer diameter D | 47 mm |
| Width B | 22.2 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 21.6 kN |
| Basic static load rating C0 | 12.7 kN |
| Fatigue load limit Pu | 0.54 kN |
| Reference speed (thermal) | 17000 rpm |
| Limiting speed (mechanical) | 14000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 180 g |
| Manufacturer designation | 3303 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 | 0.669 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.874 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 15 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) | 2 of 20 |
| Bore above smallest 3300-series size | 2 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 3303-A-2Z | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 17×47×22.2 mm envelope with catalogue ratings within 10 %; 3303 A-2Z is the stamped steel cage, shields (-2Z) execution of this size — boundary dimensions interchangeable, execution differs. |
| 3303-A-2RS1 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 17×47×22.2 mm envelope with catalogue ratings within 10 %; 3303 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 3303-ATN9 model number is decoded
3303 ATN9 is SKF's 17 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, 17×47×22.2 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 17×47×22.2 mm (0.669×1.85×0.874 in), 15.0 mm radial section height, C 21.6 kN, C0 12.7 kN, Pu 0.54 kN.reference speed 17,000 r/min (thermal) and limiting speed 14,000 r/min (mechanical), catalogue mass 180 g. Load balance: C0 12.7 kN against C 21.6 kN gives a 0.59 ratio, typical of a double-row bidirectional design; Pu 0.54 kN enters the SKF adjusted-life equation rather than the basic rating life. Sizing arithmetic on the 17 mm bore: 21.6 kN C divided by the 15.0 mm radial section height gives 1.4 kN per section millimetre; the 180 g mass and 3 % Pu/C share frame the light-load floor for the adjusted-life check. Speed-ratio note for this exact unit: the reference speed is 17,000 r/min against a 14,000 r/min limiting speed, i.e. a reference-to-limit ratio of 1.21.
Typical equipment & failure modes
Common applications
- textile machinery roller drives
- small two-bearing-housing arrangements
- small double-supported gear shafts needing two-direction location in one bearing
Known failure patterns
- two-direction thrust overload concentrating load on one row and spalling its raceway
- loss of controlled axial clearance (CB) after thermal growth removes residual play
- TN9 cage embrittlement in a hot gearbox position beyond the 120 °C polymer ceiling
- electrical pitting on VFD-driven shafts without grounding protection
- electrical pitting on VFD-driven shafts without grounding protection
Selection pitfalls — read before you substitute
- Catalogue ratings of 21.6/12.7 kN apply to the ATN9 execution; the D and DNRCBM two-piece-ring executions carry their own figures on their own pages.
- Compared with a single-row pair of the same bore, the double-row 3303 occupies less axial space but offers less freedom to adjust preload — do not substitute without re-checking the arrangement.
- A capped 3303-2Z/-2RS1 execution of this envelope exists for sealed-for-life duty; an open double-row bearing needs application sealing and a defined lubricant supply.
- The D executions have a two-piece inner ring: mount both halves square to each other, never press on the outer ring, and keep the split faces clean during fitting.
- Catalogue ratings are SKF PUB BU/P1 17000 figures for 3303 ATN9 as the double atn9 execution; the other order numbers of the 3303 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 3303-ATN9?
3303 ATN9 measures 17 mm bore × 47 mm OD × 22.2 mm width (0.669 × 1.85 × 0.874 in), mass about 180 g. SKF 17000 ratings: C 21.6 kN, C0 12.7 kN, Pu 0.54 kN, reference speed 17,000 r/min (thermal) and limiting speed 14,000 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 3303 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.