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.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 310 mm d = 170 B = 52 mm side section front view
Principal dimensions: bore d 170 mm, outer diameter D 310 mm, width B 52 mm. Schematic, not to scale.

Specification table

ParameterValue
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 modelBrandMatch levelNote
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.