Fafnir2MM9115WISUMSuper Precision Angular Contact Ball Bearing – Straight Bore, 75 mm ID, 115 mm OD, 20 mm Width, Open, 15° Contact Angle, Medium Preload, Phenolic Outer-Land-Riding Cage, ISO P4S

Product Description

What this part is

Fafnir 2MM9115WI SUM super precision angular contact ball bearing, single row, 9100WI spindle series. Manufacturer Part Number: 2MM9115WI SUM. World Part Number: 7015C-T-P4S-SUM. Bore: 75 mm. Outside Diameter: 115 mm. Bearing Width: 20 mm. Total Width: 20 mm. Number Of Rows: 1. 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 9115 is a 7015 envelope at 75 x 115 x 20 mm. WI: low shoulder on both rings. CR: phenolic outer land riding cage. SU: single universally ground. M: medium preload. Precision Class: ISO P4S, equivalent to ABEC 7/9. Preload: Medium. Mounting Arrangement: Universal single.

Published ratings

Dynamic Radial Load Rating – 1M Revs (C1): 51,600 N (11,600 lbf). C1 ISO Dynamic Radial Rating, per row: 46,800 N (10,500 lbf). Static Radial Load Rating (C0): 43,500 N (9,790 lbf). Limiting Speed, grease: 11,000 rpm. Limiting Speed, oil: 22,000 rpm. These are single-bearing figures.

Mounting dimensions

Max Shaft Fillet Radius: 1 mm. Outer Ring To Clear Radius: 1 mm. Shaft Backing Shoulder Diameter: 82.7 mm. Housing Backing Shoulder Diameter: 107.3 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.

Medium preload sits between light and heavy: more axial and radial rigidity than a light set, and lower running heat than a heavy one. It is the general-purpose machine-tool spindle setting. Internal Clearance: N/A — a preloaded bearing is defined by its preload rather than by a clearance class. Lubricant: grease or oil, and Timken publishes a limiting speed for each.

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: 1 Pc. Rows per Set: single. Universal grinding means one bearing runs alone, or several stack back to back, face to face or in tandem and reach the medium preload of the set.

Interchange guidance

Base Number: 7015. MPN Variants: 2MM9115WISUM, 2MM9115WI SUM, 2MM9115WI-SUM, 2MM-9115-WI-SUM, 2MM9115WICRSUM, 7015C, 7015-C. Same-envelope 15° medium-preload super precision equivalents are written SKF 7015 CDGB/P4A, FAG B7015-C-T-P4S-UM and NSK 7015C. Cage material and precision class vary between makers inside those designations. The line passed from Fafnir to Torrington to Timken, and Timken lists 2MM9115WI SUM today.