MRC312RDSMatched Angular Contact Ball Bearing Set – 60 mm Bore x 130 mm OD x 31 mm Width, 15°, Universally Ground

Product Description

What this part is:

MRC 312RDS matched set of single-row angular contact ball bearings, medium series, universally ground to a preload requirement. Bore: 60 mm. Outside Diameter: 130 mm. Overall Width: 31 mm per bearing. Total Width: 62 mm as a mounted set. Contact Angle: 15°. Preload: Universally ground to a preload requirement. Number Of Rows: 1 per bearing. Rolling Elements: Balls. Bore Type: Straight. Closure Type: Open both faces. Material: Chrome steel. Unit Quantity: 2 Pcs.

Decoding the designation:

300 — MRC’s medium series. At a 60 mm bore the medium series runs to a 130 mm outside diameter and a 31 mm width, which is where its load rating comes from.

12 — the bore code. Multiplied by five it gives Bore: 60 mm.

R — Contact Angle: 15°, with a counterbored outer ring. The counterbore admits a full ball complement past a low shoulder, and the high shoulder opposite carries the thrust.

DS — universally ground to a preload requirement. The bearings stack in any of the three duplex orientations — back-to-back, face-to-face or tandem — and the ground face offset produces the designed preload when the set is clamped.

What these specs mean in practice:

Contact Angle: 15° is the shallow end of the angular contact range, giving the highest speed capability of the family and the lowest heat generation, with moderate one-direction thrust per bearing. Preload: Universally ground to a preload requirement means the set is built at the grinder rather than at the bench — no shim stack, no measured end play, no reliance on the fitter to reproduce a torque. Mounted as a pair the set takes thrust in both directions and holds the shaft against an overturning moment. Bore: 60 mm. Outside Diameter: 130 mm. Overall Width: 31 mm per bearing.

Quantity and configuration:

Unit Quantity: 2 Pcs. A universally ground matched set, straight bore, open on all faces, supplied together.

Fitting notes:

The ring faces are marked, and the marks are lined up according to the orientation chosen so the ground offset closes as the set is clamped. Both inner rings are clamped against each other and both outer rings against the housing. The high-shoulder side of each outer ring faces its thrust load. Mounting force is applied through the ring being fitted and is never transmitted across the balls.

Interchange guidance:

60 x 130 x 31 mm is the 7312 envelope. A 7312 C is the 15° execution and matches on both angle and envelope, so the substitute has to be universally ground to a preload requirement.

Searchable variants:

312RDS, 312-R-DS, 312 R DS, 312RD S, 7312, MRC 312RDS.