SKF71936CDP4ATBTBSuper-Precision Angular Contact Ball Bearing Set – 180 mm ID, 250 mm OD, 33 mm Width Each, Open, 15° Contact Angle, TBTB Triplex, 3 Pcs

Product Description

What this part is

SKF 71936 CD/P4A TBTB matched set of super-precision angular contact ball bearings. Series: 719, extra-light section. Bore: 180 mm. Outside diameter: 250 mm. Width: 33 mm per bearing. Contact Angle: 15°. Open on both faces. Country of origin: Italy. Order code on the carton: VJ150. Searchable forms include 71936CDP4ATBTB, 71936 CD/P4ATBTB and 7936.

Decoding the designation

CD: high-capacity D design at a 15° contact angle. TBTB: a factory-matched triplex arrangement — two bearings in tandem with the third mounted back-to-back against them. Precision Class: P4A, SKF’s super-precision class, equivalent to ABEC 7. VJ150: SKF matched-set order code, carried here as a searchable variant.

What these specs mean in practice

A TBTB triplex takes heavy thrust in the tandem direction and locates the shaft in both directions, which is the arrangement used at the front position of a heavily loaded machine tool spindle. The two tandem bearings share the main thrust so each carries a fraction of it, raising the load the position can hold and the life it reaches at that load. Dynamic Load Rating: 148 kN. Static Load Rating: 212 kN. Limiting Speed: 3,400 rpm.

Quantity and configuration

Three bearings, factory matched and ground as a set. Stacked width of the set: 99 mm. Rings are marked for orientation, and the set is mounted in the marked order.

Fitting notes

Straight bore on a cylindrical shaft seat. Matched sets carry their preload built in, so Internal Clearance reads N/A. Cage: machined, phenolic. Lubricant: oil. Operating range: -30 °C to 120 °C.

Interchange guidance

Base number: 71936. FAG equivalent: B71936-C-T-P4S. Fafnir equivalent on the same envelope: 2MM9336WI. SKF 71936 CDGA/P4A is the universally matchable single on the same 180 x 250 x 33 mm envelope, and 71936 ACD/P4ATBTB carries a 25° contact angle — each a related size rather than a direct substitution for a matched TBTB triplex.