7311-BEP bearing: complete specifications & equivalents

Specification table

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.

Cross references & equivalents

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 7311-BEP model number is decoded

7311 BEP is SKF's 55 mm-bore single-row angular-contact ball bearing in the 7300 series, nominal 40° (B) contact angle, 55×120×29 mm to the ISO dimension plan. 40° contact angle (suffix B): the steep standard single-row angle, giving the highest axial capacity at the cost of speed, with a recommended load ratio Fa/Fr ≥ 1. E marks the optimized internal design with an enhanced ball complement and race geometry. glass-fibre reinforced PA66 cage, ball-centred (suffix P), with a 120 °C continuous-temperature ceiling. The plain BEP is a basic single bearing: its faces are not ground for universal matching, so defined pairs require the BECBP execution rather than two arbitrary BEP units.. Envelope 55×120×29 mm (2.165×4.724×1.142 in), 32.5 mm radial section height, C 79.3 kN, C0 55 kN, Pu 2.32 kN.reference speed 7,000 r/min (thermal) and limiting speed 6,700 r/min (mechanical), catalogue mass 1400 g. Envelope economics: the 29 mm width over a 32.5 mm section yields 0.89 mm of ring width per section millimetre, and the bearing weighs 1400 g for 79.3 kN of dynamic capacity — about 18 g per rated kN. Mass and section check: 1400 g inside the 55×120×29 mm outline leaves a 32.5 mm radial section, and the 55 kN static rating is 0.69× the dynamic rating — plan static safety and minimum load against those numbers rather than against sister executions. Bore-to-OD planning: OD 120 over bore 55 is a 2.18× step for this size, and the 29 mm width gives a bore/width ratio of 1.90; use these ratios when housing space around the 55 mm shaft is the first constraint. Basic polymer-cage execution: BEP is delivered as an individual open bearing with the 40-degree optimized internals and a glass-fibre PA66 ball-centred cage; it is not ground on the side faces for arbitrary pairing, so a reversing-thrust position should order BECBP for a set rather than mounting two unmatched BEP units.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Reference and limiting speeds are different ceilings: design to both, and remember preload and oil/air cooling move the real thermal limit far from the catalogue reference value.
• Assign interference to the rotating ring — roughly k5 on a 55 mm rotating shaft with an H7 housing — and let the stationary ring slide for axial setting; reverse the logic if the outer ring rotates.
• Assign interference to the rotating ring — roughly k5 on a 55 mm rotating shaft with an H7 housing — and let the stationary ring slide for axial setting; reverse the logic if the outer ring rotates.
• Fillet radii must clear the chamfer so the 29 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
• The steep 40° angle of 7311-BEP favours thrust-heavy combined loads; for a predominantly radial high-speed position the 25° ACCBM execution of the same size is the alternative order number.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 7311 BEP as the single basic pa66 execution; the other order numbers of the 7311 size are different products and may carry different ratings — always quote the full designation when purchasing.