Fafnir2MM9118WI-SULSuper Precision Angular Contact Ball Bearing, Single Universally Ground, 90 x 140 x 24 mm, 15 Degree Contact Angle, Light Preload, Phenolic Outer-Land-Riding Cage, ABEC 7/9

Product Description

What this part is

Fafnir 2MM9118WI-SUL, a Timken super precision angular contact ball bearing for machine tool spindles, supplied as a single universally ground bearing at light preload. Brand: Fafnir (Timken). Bore: 90 mm. Outside Diameter: 140 mm. Overall Width: 24 mm. Contact Angle: 15°. Preload: Light. Precision Rating: ISO P4S (ABEC 7/9). Arrangement: SU, single universally ground. Number Of Rows: 1. Cage Type: CR — Phenolic Outer Land Riding Cage. Cage Material: Phenolic, Timken cage designation MBR. Ball Type: Steel. Bearing Material: Chrome steel. Closure Type: Open. Bore Type: Straight. Lubricant: Oil. Series: 9100WI. Base Number: 2MM9118WI. Design Units: Metric. Item Weight: 2.4 lb. Harmonization Code: 8482.10.50. Timken World Part Number: 7018C-T-P4S-SUL.

Published ratings and mounting data

Dynamic Load Rating, per row: 72,200 N / 16,200 lbf (C1 ISO). Static Radial Load Rating (C0): 68,900 N / 15,500 lbf. Dynamic Load Rating (C1), duplex set of two: 79,600 N / 17,900 lbf. Limiting Speed, grease: 9,200 rpm. Limiting Speed, oil: 18,400 rpm. Maximum Shaft Fillet Radius: 1.5 mm. Shaft Backing Shoulder Diameter: 99.7 mm. Housing Backing Shoulder Diameter: 130.9 mm. Outer Ring To-Clear Radius: 1.5 mm.

Decoding the designation

2MM: Fafnir super precision metric series, 15° contact angle. 9118: 9100WI dimension series, bore code 18, 90 mm bore, ISO 7018 envelope. WI: low shoulder on both rings. CR: phenolic outer land riding cage, Timken designation MBR. SU: single universally ground. L: light preload. The MM prefix carries ISO P4S. Searchable forms: 2MM9118WI-SUL, 2MM9118WISUL, 2MM-9118-WI-CR-SUL, 2MM9118WICRSUL, 2MM 9118 WI SUL, 2MM9118WI, 7018C-T-P4S-SUL, 7018C, 7018.

What these specs mean in practice

The 15° contact angle is the speed-biased choice. A shallower angle keeps the ball load line closer to radial, reducing ball spin, gyroscopic moment and cage loading, so the bearing runs cooler and faster than a 25° bearing in the same envelope. It gives up axial stiffness and thrust capacity in exchange.

Light preload points the same way: lowest friction, least heat, longest grease life, at the cost of axial stiffness. At 90 mm bore that matters, because surface speed at the ball track is already high against a 9,200 rpm grease limit.

The phenolic outer land riding cage is what makes those speeds usable at this size. Phenolic is light and mildly self-lubricating, so it generates far less heat than a steel cage, and riding on the outer ring land lets centrifugal force stabilise the cage rather than load it.

Universal grinding is the flexible part of the specification. A single SUL bearing runs on its own, and two identical SUL bearings assemble back-to-back, face-to-face or in tandem to form a matched pair without shims. The 79,600 N C1 figure above is the rating for that pair; a single bearing carries the 72,200 N per-row rating.

Quantity and configuration

Unit Quantity: 1 Pc. SUL designates a single universally ground bearing, so the sale unit is one bearing. Total Width: 24 mm.

Interchange guidance

Timken’s published world equivalent is 7018C-T-P4S-SUL. A matching substitute carries the 15° contact angle, ISO P4S grade, phenolic cage and light preload alongside the 90 x 140 x 24 mm envelope. Same-envelope related sizes: SKF 7018 CDGA/P4A, NSK 7018CTRSULP4, the 25° 3MM9118WI or 7018E, and clearance-graded or steel-caged 7018 bearings. Fafnir super precision bearings are supplied under the Timken brand, so Fafnir and Timken designations of this form are the same product line.