SKFSuper-Precision Angular Contact Ball Bearing – 140 mm ID, 210 mm OD, 33 mm Width, 15° Contact Angle, Open, ABEC 5, Light Preload

Product Description

What this part is

SKF 7028 C TC C78 single-row super-precision angular contact ball bearing. Bore: 140 mm. Outside diameter: 210 mm. Width: 33 mm. Series: 70, light section. Open on both faces, straight bore, phenolic cage. The carton also carries the Fafnir designation 2M9128WI and the New Departure designation Q0L28DTL5.

Decoding the designation

7028: series 70, bore code 28, 140 mm bore. C: 15° contact angle. Precision Class: ABEC 5 / P5, marked on the carton. The Fafnir 9128WI number is the same 7028 envelope and the New Departure Q0L28 reads the same way: Q = phenolic separator, 0L28 = ISO 7028, DTL = duplex tandem at light preload, 5 = ABEC 5.

What these specs mean in practice

Basic dynamic load rating: 153 kN. Basic static load rating: 176 kN. On SKF’s 70-series light section the static figure sits above the dynamic one, which is normal for this section and reflects a large ball complement on a thin cross-section. A 15° contact angle favours speed and radial stiffness; light preload holds shaft position without adding heat. Limiting speed: 3,800 rpm. Operating temperature range: -30 to +120 °C, set by the phenolic cage.

Quantity and configuration

One bearing, 1 Pc, out of a factory duplex tandem set. Universally matchable, so it mounts alongside another piece of the same execution back-to-back, face-to-face or in tandem, and it also runs on its own.

Fitting notes

Straight bore, open on both faces. The bearing takes axial load in one direction and locates against square shoulders on both rings. Light preload comes out as ground when the rings are clamped.

Interchange guidance

Timken/Fafnir 2MM9128WI and NSK 7028CTYNSULP4 are the same 140 x 210 x 33 mm size at 15° with light preload. New Departure Q0L28DTL5 is the same size and class. SKF 7028 ACD/P4A is a related size at a 25° contact angle. Searchable forms: 7028CTCC78, 7028 C TC C78, 7028-C-TC-C78, 7028C.