3310-A bearing: complete specifications & equivalents
The 3310-A 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 | steel, stamped ribbon (J-type) |
| 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 A |
| 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-ATN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 50×110×44.4 mm envelope with catalogue ratings within 10 %; 3310 ATN9 is the glass-fibre PA66 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-A model number is decoded
3310 A 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. with no cage suffix the double-row A execution uses the standard stamped steel ball-centred cage. 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. Mass and section check: 1700 g inside the 50×110×44.4 mm outline leaves a 30.0 mm radial section, and the 64 kN static rating is 0.71× the dynamic rating — plan static safety and minimum load against those numbers rather than against sister executions. 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. Speed-ratio note for this exact unit: the reference speed is 6,700 r/min against a 6,000 r/min limiting speed, i.e. a reference-to-limit ratio of 1.12.
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
- snap-ring groove or two-piece-ring damage when the D execution is pressed home through the wrong ring
- two-direction thrust overload concentrating load on one row and spalling its raceway
- stamped steel cage noise and pocket wear in marginal-lubrication starts, where a brass-cage execution would survive
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- electrical pitting on VFD-driven shafts without grounding protection
Selection pitfalls — read before you substitute
- Catalogue ratings of 90/64 kN apply to the A execution; the D and DNRCBM two-piece-ring executions carry their own figures on their own pages.
- 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.
- 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.
- Controlled axial clearance is the heart of the design: the A execution is produced to the standard double-row axial clearance; check residual clearance after mounting and at operating temperature.
- Catalogue ratings are SKF PUB BU/P1 17000 figures for 3310 A as the double a steel 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-A?
3310 A 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 A suffix mean?
A on a double-row bearing means no filling slots, so both rows carry their full ball complement in both directions. with no cage suffix the double-row A execution uses the standard stamped steel ball-centred cage.
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 A?
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.