MRC111KRExtra-Light Angular Contact Ball Bearing – 55 mm Bore x 90 mm OD x 18 mm Width, 15°, Counterbored Outer Ring

Product Description

What this part is

MRC 111KR single-row angular contact ball bearing, extra-light series, with a counterbored outer ring. Bore: 55 mm. Outside Diameter: 90 mm. Overall Width: 18 mm. Contact Angle: 15°. Number Of Rows: 1. Rolling Elements: Balls. Bore Type: Straight. Closure Type: Open both faces. Material: Chrome steel. Unit Quantity: 1 Pc.

Decoding the designation

100K — MRC’s extra-light series. Only 17.5 mm of radial section separates a 55 mm shaft from a 90 mm housing bore, which is what puts a large shaft inside a compact head.

11 — the bore code. Multiplied by five it gives Bore: 55 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.

What these specs mean in practice

Contact Angle: 15° is the shallow end of the angular contact range. It gives the highest speed capability of the family and the lowest heat generation, and it suits moderate one-direction thrust alongside a substantial radial load — the standard trade for a machine-tool spindle or a high-speed gearbox input. The counterbored outer ring makes the bearing directional, and it is normally run against a second bearing facing the opposite way, or as one half of a duplex set. Bore: 55 mm. Outside Diameter: 90 mm. Overall Width: 18 mm.

Quantity and configuration

Unit Quantity: 1 Pc. One single-row bearing, straight bore, open on both faces, counterbored outer ring.

Fitting notes

The high-shoulder side of the outer ring faces the thrust load, so the bearing is fitted with the counterbore turned away from the direction the axial force arrives from. Mounting force is applied through the ring being fitted and is never transmitted across the balls. Where two of these run opposed on one shaft, axial position is set by a spacer or by clamping to a measured end play. On a light section the ring takes the shape of the seat it sits in, so shaft and housing roundness matter.

Interchange guidance

55 x 90 x 18 mm is the 7011 envelope and the carton carries the 7011C cross itself. A 7011 C is the 15° execution and matches on both angle and envelope, so it is a genuine interchange. A 7011 at 25° or 40° carries different thrust capacity and stiffness on the same envelope and is a related size.

Searchable variants

111KR, 111-KR, 111 KR, 7011-KR, 7011C, 7011-C, MRC 111KR.