7238-BCBM 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 7238-BCBM model number is decoded

7238 BCBM is SKF's 190 mm-bore single-row angular-contact ball bearing in the 7200 series, nominal 40° (B) contact angle, 190×340×55 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 190×340×55 mm (7.48×13.386×2.165 in), 75.0 mm radial section height, C 307 kN, C0 405 kN, Pu 10.4 kN.reference speed 2,000 r/min (thermal) and limiting speed 2,600 r/min (mechanical), catalogue mass 22000 g. Selection figures for 7238 BCBM: the static-to-dynamic ratio C0/C is 1.32, Pu 10.4 kN is about 3 % of C, and catalogue mass works out to roughly 116 g per millimetre of bore. At the printed limiting speed of 2,600 r/min the mean pitch diameter dm ≈ 265.0 mm implies a dn value around 689k mm·r/min; the 2,000 r/min reference speed is the thermal-planning figure under catalogue load. Bore-to-OD planning: OD 340 over bore 190 is a 1.79× step for this size, and the 55 mm width gives a bore/width ratio of 3.45; use these ratios when housing space around the 190 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

Selection pitfalls — read before you substitute

• One 7238-BCBM locates the shaft in one axial direction only; reversing-thrust positions need a DB or DF pair — or a double-row bearing — with preload set from the load diagram, never from assembly feel.
• Fillet radii must clear the chamfer so the 55 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
• 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.
• 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.
• The steep 40° angle of 7238-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.