Fafnir2MM9118WI-DULSuper-Precision Angular Contact Ball Bearing – 90 mm ID, 140 mm OD, 24 mm Width, Open, 15° Contact Angle, Phenolic Cage, Light Preload, Duplex Pair

Product Description

What this part is

Fafnir 2MM9118WI-DUL super-precision angular contact ball bearing, supplied as a universally ground duplex pair. Bore: 90 mm. Outside Diameter: 140 mm. Bearing Width: 24 mm. Total Width: 48 mm. Series: Fafnir 9100WI spindle series, ISO 7018 envelope. Timken World Part Number: 7018C-T-P4S-DUL. Rolling Elements: steel balls. Closure Type: open on both faces. GTIN: 087796072961.

Decoding the designation

2MM is the Fafnir super-precision prefix. Contact Angle: 15°. Precision Rating: ISO P4S (ABEC 7/9). In the 9100WI series the last two digits are the bore code, so 18 is 90 mm. DUL is duplex, universally ground, light preload, which is why two bearings make one set. Preload: Light. Searchable forms of the number include 2MM9118WI-DUL, 2MM9118WIDUL and 2MM 9118 WI DUL.

What these specs mean in practice

Dynamic Radial Load Rating (C1, set): 79.6 kN / 17,900 lbf. Dynamic Radial Load Rating (C1, per row): 72.2 kN / 16,200 lbf. Static Radial Load Rating (C0): 68.9 kN / 15,500 lbf. Limiting Speed, grease: 9,200 rpm. Limiting Speed, oil: 18,400 rpm. Cage Type: CR – Phenolic Outer Land Riding Cage. The 15° contact angle favours speed and radial stiffness; a 25° bearing in the same envelope trades speed for thrust capacity. The phenolic outer-land-riding cage is light and quiet at speed, and the oil limiting speed is double the grease figure. Light preload holds running heat and thermal growth down. P4S tolerances hold bore, outside diameter, width and runout to the grade machine tool spindles are built around.

Mounting dimensions

Shaft Backing Shoulder Diameter: 99.7 mm (3.930 in). Housing Backing Shoulder Diameter: 130.9 mm (5.160 in). Maximum Shaft Fillet Radius: 1.5 mm (0.059 in). Outer Ring To Clear Radius: 1.5 mm (0.059 in).

Quantity and configuration

Two bearings, one duplex pair. Unit Quantity: 2 Pcs. Arrangement: universally ground, mountable back to back, face to face or in tandem, reaching the ground light preload when clamped solid.

Interchange guidance

Direct equivalents at 90 x 140 x 24 mm with a 15° angle and light-preload duplex grinding are SKF 7018 CD/P4ADGA, NSK 7018CTYNDULP4, FAG B7018-C-T-P4S-DUL and SNR 7018CVDUJ74. The 3MM9118WI version of this number is a 25° bearing in the same envelope, a related size rather than a substitution, and a 71918 is a different envelope at 90 x 125 x 18 mm.