MRC307SWIDeep Groove Ball Bearing 35x80x21 mm, Extended Inner Ring, Open Both Faces, 6307 Envelope

Product Description

What this part is

An MRC 307SWI single-row deep groove ball bearing with an extended inner ring — 35 mm bore, 80 mm outside diameter, 21 mm outer ring width. The bearing is open on both faces. Apart from the inner ring extension it is the 6307 envelope, so it drops into a standard 6307 housing bore while giving a longer inner ring contact length on the shaft.

Decoding the designation

307 – MRC 300-series single-row deep groove ball bearing, 35 mm bore; the ISO 6307 envelope
S – MRC single-row ball bearing type code
WI – extended (wide) inner ring; the inner ring projects axially beyond the outer ring
No closure suffix, so both faces are open
No clearance suffix, so internal clearance is normal (CN)

What these specs mean in practice

The extended inner ring spreads the clamp load over a longer length of shaft, which reduces fretting under a heavy interference fit and gives a longer seat for a shoulder, spacer or collar to bear against. It also lets the bearing be located in the housing without a separate inner spacer. Because the outer ring stays at the standard 6307 21 mm width, the housing bore, retaining ring groove and end cap can remain unchanged. Normal CN clearance suits a light interference fit on the shaft with a moderate temperature rise between the rings.

Published specifications

Bore: 35 mm (1.3780 in)
Outside diameter: 80 mm (3.1496 in)
Outer ring width: 21 mm (0.8268 in)
Inner ring: extended beyond the outer ring
Rows: 1
Rolling elements: balls
Closure: open both faces
Internal clearance: CN (normal)
Material: through-hardened bearing steel

Quantity and configuration

Sold as 1 Pc. One complete bearing, open on both faces, with the extended inner ring integral to the bearing. No collar, snap ring, spacer or seal is included.

Fitting notes

Mounting force is applied to the ring being fitted so that no load passes through the balls; on this bearing the extended inner ring gives a convenient press face. The housing bore accepts the bearing as a standard 6307 width, and axial clearance is checked between the projecting inner ring and any adjacent seal or cap. The open faces take lubricant from the housing cavity.

Interchange guidance

An interchange must also have the extended inner ring: a plain 6307 shares the 35 x 80 x 21 mm envelope but has flush ring faces, so it will not provide the extra shaft seat length and is a related size rather than an equivalent. Equivalents are extended-inner-ring 6307-envelope bearings such as Fafnir 307WI series and equivalent wide-inner-ring 6307 designs from other makers.