Fafnir3MM9112WIDULSuper-Precision Angular Contact Ball Bearing Pair – 60 mm ID, 95 mm OD, 18 mm Width Each, 25° Contact Angle, Phenolic Cage, Light Preload

Product Description

What this part is

A Timken Fafnir 3MM9112WI-CR-DUL super-precision angular contact ball bearing, supplied as a matched pair. Bore 60 mm, outside diameter 95 mm, width 18 mm per bearing, 36 mm across the assembled pair. Open on both faces, with a machined fabric-base phenolic cage riding on the outer ring lands.

Decoding the designation

The leading 3MM sets a 25° contact angle. The MM prefix denotes Fafnir super-precision execution to P4S, equivalent to ABEC 7/9. The 9100 series number decodes to the ISO 70 light series, so 9112 is the ISO 7012 envelope at 60 x 95 x 18 mm. CR is the phenolic cage. DUL is a universally matchable duplex pair set to light preload.

What these specs mean in practice

A 25° contact angle carries more thrust and tolerates less speed than a 15° bearing of the same envelope. Light preload is the high-speed grade of the ladder: it generates the least friction and heat of the three and permits the highest running speed, while giving up stiffness to the medium and heavy settings. Because the pair is preload-set rather than clearance-set, internal clearance is not applicable to it.

Quantity and configuration

Two bearings, sold as a matched set. Universally matchable duplex construction allows the pair to be mounted back-to-back, face-to-face or in tandem, the ground faces producing the specified light preload when clamped.

Fitting notes

The rings are ground as a set and stay together. Clamping is applied evenly against the ground faces so the designed preload is established without ring distortion. The phenolic cage suits oil lubrication and sustained high speed.

Interchange guidance

The same-specification equivalent is SKF 7012 ACD/P4A DGA. A 3MM9112WI-DUM or -DUH set shares the envelope and contact angle at a heavier preload, and a 7012 CD or C variant shares the envelope at a 15° contact angle; both are related sizes rather than interchanges.