7234-BCBM bearing: complete specifications & equivalents
The 7234-BCBM is a ISO 15 radial bearing sized 170 x 310 x 52 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 170 mm |
| Outer diameter D | 310 mm |
| Width B | 52 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 281 kN |
| Basic static load rating C0 | 345 kN |
| Fatigue load limit Pu | 9.5 kN |
| Reference speed (thermal) | 2400 rpm |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 17500 g |
| Manufacturer designation | 7234 BCBM |
| 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 & 7200-series range
| Bore d | 6.693 in |
|---|---|
| Outer diameter D | 12.205 in |
| Width B | 2.047 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in 7200-series | 10 mm |
| Largest outer diameter in 7200-series | 540 mm |
| Width range across 7200-series | 9–85 mm |
| Bore position in 7200-series (smallest first) | 29 of 36 |
| Bore above smallest 7200-series size | 160 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| QJ-234-N2MA | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 170×310×52 mm envelope, but catalogue C/C0 differ between executions (281/345 kN vs 455/720 kN) — boundary dimensions match, not a load-rating equivalent. |
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 7234-BCBM model number is decoded
7234 BCBM is SKF's 170 mm-bore single-row angular-contact ball bearing in the 7200 series, nominal 40° (B) contact angle, 170×310×52 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. machined brass cage, ball-centred (suffix M), the choice for high speed, marginal lubrication and shock duty. CB means universally matchable with Normal axial internal clearance: the two side faces are ground so any two units form DB (back-to-back), DF (face-to-face) or DT (tandem) sets without regrinding. Envelope 170×310×52 mm (6.693×12.205×2.047 in), 70.0 mm radial section height, C 281 kN, C0 345 kN, Pu 9.5 kN.reference speed 2,400 r/min (thermal) and limiting speed 2,800 r/min (mechanical), catalogue mass 17500 g. Envelope economics: the 52 mm width over a 70.0 mm section yields 0.74 mm of ring width per section millimetre, and the bearing weighs 17500 g for 281 kN of dynamic capacity — about 62 g per rated kN. Speed planning distinguishes the two published ceilings mechanically: the cage and balls tolerate 2,800 r/min while thermal balance under catalogue load sets the 2,400 r/min reference; at dm ≈ 240.0 mm the corresponding dn is approximately 672k mm·r/min. Bore-to-OD planning: OD 310 over bore 170 is a 1.82× step for this size, and the 52 mm width gives a bore/width ratio of 3.27; use these ratios when housing space around the 170 mm shaft is the first constraint. Non-optimized universal execution: BCBM keeps the earlier internal geometry (no E) with CB Normal-clearance set mounting and a machined brass ball-centred cage; it is stocked for positions built around its established ratings rather than the enhanced E ball complement.
Typical equipment & failure modes
Common applications
- vertical mill separator drives
- heavy industrial gearboxes
- large process pumps and compressors
Known failure patterns
- preload loss as a loosely clamped set runs slack and the balls smear the raceways
- thermal preload runaway in a back-to-back pair when inner-ring heat cannot expand away
- ball skidding when Fa/Fr stays below the 1,0 (40°) or 0,55 (25°) ratio and the contact ellipse is unloaded
- set preload miscalculation because the non-E BCBM geometry differs in stiffness from E executions despite matching CB faces
- hard-particle indentation of the asymmetric raceway in unfiltered oil
- mounting score marks when the bearing is cocked over a burr or keyway
Selection pitfalls — read before you substitute
- Preload the set against a calculated stand-off dimension — the ground faces of BCBM establish it, but locknut torque, sleeve crush and housing-face squareness each consume part of the allowance.
- Keep the load ratio in the SKF design range: Fa/Fr ≥ 1 for this angle; below it the balls unload the contact ellipse and skid, which is why the catalogue insists on a minimum axial load (Fam ≈ A·(n·dm/1000)²) at high speed.
- Assign interference to the rotating ring — roughly m6 on a 170 mm rotating shaft with an H7 housing — and let the stationary ring slide for axial setting; reverse the logic if the outer ring rotates.
- Preload the set against a calculated stand-off dimension — the ground faces of BCBM establish it, but locknut torque, sleeve crush and housing-face squareness each consume part of the allowance.
- The steep 40° angle of 7234-BCBM 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.
- Universally matchable BCBM bearings arrive ready for set mounting, not preloaded sets: preload results from how the set is clamped, so follow the SKF stand-off-ring and nut-torque procedure.
Frequently asked questions
What are the dimensions and catalogue data of 7234-BCBM?
7234 BCBM measures 170 mm bore × 310 mm OD × 52 mm width (6.693 × 12.205 × 2.047 in), mass about 17500 g. SKF 17000 ratings: C 281 kN, C0 345 kN, Pu 9.5 kN, reference speed 2,400 r/min (thermal) and limiting speed 2,800 r/min (mechanical).
What does the BCBM suffix mean?
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. machined brass cage, ball-centred (suffix M), the choice for high speed, marginal lubrication and shock duty. CB means universally matchable with Normal axial internal clearance: the two side faces are ground so any two units form DB (back-to-back), DF (face-to-face) or DT (tandem) sets without regrinding.
What do the reference and limiting speeds mean for 7234-BCBM?
The 2,400 r/min reference (thermal) and 2,800 r/min limiting (mechanical) speeds are catalogue conditions; preload, lubrication and heat removal move the permissible value, so re-calculate for the actual arrangement.
Can one 7234-BCBM take thrust in both directions?
No. A single-row angular-contact bearing reacts axial load in one direction; reversing thrust needs a DB/DF matched pair (use a universally matchable CB/GA execution) or a double-row bearing. Under radial load the 40° angle induces an axial force that the arrangement must balance.
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.