Fafnir2MM9118WI-DULSuper Precision Angular Contact Spindle Bearing, Matched Duplex Pair, 90 x 140 x 24 mm, 48 mm Total Width, 15 Degree Contact Angle, Light Preload, Phenolic Outer Land Riding Cage, P4S

Product Description

What this part is

Fafnir 2MM9118WI-DUL super precision angular contact ball bearing set from Timken, supplied as a matched duplex pair. Brand: Fafnir (Timken). Bore: 90 mm. Outside Diameter: 140 mm. Overall Width: 24 mm per bearing. Total Width: 48 mm. Contact Angle: 15°. Preload: Light. Precision Rating: ISO P4S (ABEC 7/9). Arrangement: DU, duplex universally ground. Number Of Rows: 1 per bearing. Cage Type: CR, phenolic outer land riding cage. Cage Material: Phenolic. Ball Type: Steel. Bearing Material: Chrome steel. Closure Type: Open. Bore Type: Straight. Design Units: Metric. Series: 9100WI. Base Number: 2MM9118WI. Timken World Part Number: 7018C-T-P4S-DUL. Harmonization Code: 8482.10.50.

Published ratings and mounting data

Dynamic Load Rating (C1), duplex set, 1 million revolutions: 79,600 N / 17,900 lbf. Dynamic Load Rating per bearing, C1 ISO: 72,200 N / 16,200 lbf. Static Load Rating per bearing (C0): 68,900 N / 15,500 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 with bore code 18, giving a 90 mm bore and the ISO 7018 envelope.

WI — low shoulder on both rings.

CR — phenolic outer land riding cage.

DU — duplex universally ground.

L — light preload.

Searchable forms: 2MM9118WI-DUL, 2MM9118WIDUL, 2MM-9118-WI-DUL, 2MM9118WI DUL, 2MM9118WICRDUL, 7018C-T-P4S-DUL, 7018C, 7018.

What these specs mean in practice

A 15° contact angle keeps the ball load line closer to the radial plane. That reduces ball spin and gyroscopic moment, so the set runs cooler and faster than a 25° set in the same envelope, and it gives up axial stiffness and thrust capacity in exchange. The 25° execution in this envelope is the 3MM9118WI.

Light preload works in the same direction: lowest friction, least heat, highest speed capability of the three preload grades. The phenolic outer land riding cage is what makes those speeds usable at 90 mm bore, because phenolic is light and mildly self-lubricating and riding on the outer ring land lets centrifugal force stabilise the cage rather than load it.

Universal grinding means the ring faces are flush ground to a controlled offset, so the same pair stacks back-to-back for maximum moment stiffness, face-to-face for tolerance of slight misalignment, or in tandem to double thrust capacity in one direction.

Quantity and configuration

Unit Quantity: 2 Pcs, one matched duplex pair. Total Width: 48 mm. Outer rings are marked FAFNIR, 2MM9118WI, DUL and THRUST with a direction arrow. Bearings are in an unopened sealed factory bag inside a relabelled Timken carton carrying a factory-applied FAFNIR 2MM9118WI DUL label.

Interchange guidance

Timken publishes the world equivalent as 7018C-T-P4S-DUL. A matching substitute carries the 15° contact angle, ISO P4S grade, phenolic cage, light preload and duplex universally ground faces in the 90 x 140 x 24 mm envelope. Related sizes in the same envelope: the 25° 3MM9118WI or 7018E, the single 2MM9118WI-SUL, and clearance-graded or steel-caged 7018 bearings.