Fafnir2MM9110WIDUHSuper Precision Angular Contact Ball Bearing Duplex Pair – Straight Bore, 50 mm ID, 80 mm OD, 16 mm Width Each, Open, 15° Contact Angle, Heavy Preload, Phenolic Outer-Land-Riding Cage, ISO P4S

Product Description

What this part is

Fafnir 2MM9110WI DUH matched duplex pair of super precision angular contact ball bearings, 9100WI spindle series. Manufacturer Part Number: 2MM9110WI DUH. World Part Number: 7010C-T-P4S-DUH. Bore: 50 mm. Outside Diameter: 80 mm. Bearing Width: 16 mm per bearing. Total Width: 32 mm for the pair. Number Of Rows: 1 per bearing. Bore Type: Straight. Closure Type: Open. Rolling Elements: Steel balls. Design Units: Metric.

Decoding the designation

Contact Angle: 15°, carried by the 2MM prefix. Series: 9100WI, which maps to the ISO 70xx light section, so the 9110 is a 7010 envelope at 50 x 80 x 16 mm. WI: low shoulder on both rings. CR: phenolic outer land riding cage. DU: duplex, a factory-matched two-bearing set. H: heavy preload. Precision Class: ISO P4S, equivalent to ABEC 7/9. Preload: Heavy. Mounting Arrangement: Duplex pair.

Published ratings

Dynamic Radial Load Rating – 1M Revs (C1): 27,900 N (6,270 lbf) per bearing. C1 ISO Dynamic Radial Rating, per row: 25,300 N (5,670 lbf). Static Radial Load Rating (C0): 20,800 N (4,670 lbf) per bearing. Limiting Speed, grease: 16,300 rpm. Limiting Speed, oil: 32,600 rpm. Timken publishes these as bearing figures rather than set figures, and the same values appear on the single and the duplex listings of this bearing.

Mounting dimensions

Max Shaft Fillet Radius: 1 mm. Outer Ring To Clear Radius: 1 mm. Shaft Backing Shoulder Diameter: 56.1 mm. Housing Backing Shoulder Diameter: 74.2 mm.

What these specs mean in practice

A 15° contact angle is the high-speed setting in this family. More of the load line runs radially, the ball set does less centrifugal and gyroscopic work, and the bearing carries a higher limiting speed than the 25° execution on the same envelope.

Heavy preload is the stiffest of the three duplex settings. It holds the spindle nose closest to position under a changing cut and gives the highest axial and radial rigidity of the DUL, DUM and DUH ladder, at higher running heat. Internal Clearance: N/A — a preloaded set is defined by its preload rather than by a clearance class.

Cage Type: CR, phenolic outer land riding. Cage Material: Phenolic. A machined phenolic laminate cage is light, so it loads the ball pockets very little at speed, it is self lubricating, and it damps rather than rings. Guidance on the outer ring land keeps it stable at high speed.

Quantity and configuration

Unit Quantity: 2 Pcs. A factory-matched duplex pair, ground as a set to the heavy preload. The two bearings ship together and are the sale unit.

Interchange guidance

Base Number: 7010. MPN Variants: 2MM9110WIDUH, 2MM9110WI DUH, 2MM-9110-WI-DUH, 2-MM-9110-WI-DUH, 2MM9110WICRDUH, 7010C, 7010-C, 7010C-T-P4S-DUH. Same-envelope 15° heavy-preload duplex equivalents are written SKF 7010 CD/P4ADGC, FAG B7010-C-T-P4S-DUH and NSK 7010CTRDUHP4. Cage material and precision class vary between makers inside those designations. The line passed from Fafnir to Torrington to Timken, and Timken lists 2MM9110WI DUH today.