MRCR1909EX1Cylindrical Roller Bearing 50 x 68 x 12 mm, Thin Section

Product Description

What this part is

This is an MRC R1909EX1 cylindrical roller bearing with a 50 mm bore, 68 mm outside diameter and 12 mm width. MRC is part of the SKF group. The rollers run in line contact with the raceways rather than point contact, which is what gives a cylindrical roller bearing its high radial capacity for its size.

Section and envelope

The radial section is 9 mm, half the difference between the 68 mm outside diameter and the 50 mm bore, against a 12 mm width. That is a thin section for a 50 mm bore, so the bearing is dimensionally distinct from a standard-series cylindrical roller bearing at the same bore, which would carry a considerably larger outside diameter and width.

What these specs mean in practice

Line contact between roller and raceway gives substantially higher radial load capacity and stiffness than a ball bearing occupying the same space, at the cost of any meaningful axial load capability and with less tolerance of shaft-to-housing misalignment. A thin-section design trades some of that capacity back for a compact envelope, which is what makes it useful where housing bore and shaft diameter are both fixed by the surrounding design.

Quantity and configuration

Single bearing, 1 Pc.

Fitting notes

Mounting force is applied through the ring being fitted rather than transmitted from one ring to the other across the rollers. A thin section is less tolerant of an out-of-round or undersized housing bore than a standard section, so the seats carry the tolerance rather than the bearing.

Interchange guidance

The genuine interchange is another MRC R1909EX1. The 1909 element is MRC’s own series numbering rather than an ISO base number, so an ISO 1909 or 6909 designation from another maker is not the same bearing and is not a substitution.