Fafnir3MM9307WICRQULSuper-Precision Angular Contact Bearing Quad Set 35x55x10 mm 25° Light Preload ABEC 7/9

Product Description

What this part is

A Fafnir 3MM9307WI-CR-QUL matched quad set of super-precision single-row angular contact ball bearings. Each bearing is 35 mm bore, 55 mm outside diameter, 10 mm wide, giving 40 mm total stack width across the four. Open on both faces, universally ground as a set. The ISO envelope is the 7907 extra-light series.

Decoding the designation

3MM — 25° contact angle in the Fafnir scheme; the MM prefix carries the P4S build9307 — 35 mm bore in the extra-light section, ISO 7907 envelopeWI — super-precision spindle bearing seriesCR — phenolic outer-land-riding cageQU — quad, four bearings ground as one matched setL — light preload

What these specs mean in practice

A quad set spreads load across four rows, which raises stiffness and capacity well beyond a duplex pair in the same bore without increasing shaft diameter. The 7907 extra-light section keeps the outside diameter small for a 35 mm shaft, so the arrangement fits compact spindle noses. The 25° angle favours thrust over speed.

Published specifications

Bore: 35 mmOutside diameter: 55 mmWidth: 10 mm per bearing, 40 mm stackedContact angle: 25°Precision: P4S — ABEC 7 / ABEC 9Preload: light, factory matchedCage: phenolic, outer-land ridingRows: 1 per bearing, 4 rows as a setClosure: open

Quantity and configuration

Matched quad set. 4 Pcs per sale unit.

Fitting notes

Each bearing carries thrust in one direction, and the stacking order fixes which directions the set covers. The etched marks on the outer rings run in sequence and align to hold the matched offsets as ground.

Interchange guidance

Same-spec matched quad sets at 25°, super precision, light preload: RHP 7907ETQULP4, FAG B7907E.T.P4S.QUL, NSK 7907A5TRQULP4, SKF 7907 ACD/P4AQBCA. The 15° 2MM9307WI shares the envelope and is a related size rather than an interchange.