Fafnir3MM214WICRSuper Precision Angular Contact Ball Bearing – Straight Bore, 70 mm ID, 125 mm OD, 24 mm Width, Open, 25° Contact Angle, Phenolic Outer-Land-Riding Cage, ISO P4S

Product Description

What this part is

Fafnir 3MM214WICR super precision angular contact ball bearing, single row, 200WI spindle series. Manufacturer Part Number: 3MM214WI CR. Bore: 70 mm. Outside Diameter: 125 mm. Bearing Width: 24 mm. Total Width: 24 mm. Number Of Rows: 1. Bore Type: Straight. Closure Type: Open. Rolling Elements: Steel balls. Design Units: Metric.

Decoding the designation

Contact Angle: 25°, carried by the 3MM prefix. Series: 200WI, the Fafnir spindle angular contact range. Size code 214 carries the ISO 7214 envelope, 70 x 125 x 24 mm. WI: low shoulder on both rings. CR: phenolic outer land riding cage. Precision Class: ISO P4S, equivalent to ABEC 7/9.

Published ratings

Dynamic Radial Load Rating – 1M Revs (C1): 80,200 N (18,000 lbf). C1 ISO Dynamic Radial Rating, per row: 72,900 N (16,400 lbf). Static Radial Load Rating (C0): 57,400 N (12,900 lbf). Limiting Speed, grease: 11,300 rpm. Limiting Speed, oil: 20,600 rpm. These are single-bearing figures.

Mounting dimensions

Max Shaft Fillet Radius: 1.5 mm. Outer Ring To Clear Radius: 1.5 mm. Shaft Backing Shoulder Diameter: 80.3 mm. Housing Backing Shoulder Diameter: 115.8 mm.

What these specs mean in practice

A 25° contact angle puts more of the load line along the shaft axis, so this bearing is stiffer axially than the 15° execution on the same envelope and holds a spindle nose in position under thrust — boring, drilling, plunge milling, heavy face milling. The trade is speed: a steeper angle raises the centrifugal and gyroscopic work on the ball set, so the limiting speeds sit below those of the 15° part.

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. Its service range suits oil mist, oil air and grease for life spindles.

Quantity and configuration

Unit Quantity: 1 Pc. Rows per Set: single. The designation is the plain 3MM214WI CR base with no duplex or universal pairing suffix. The outer ring is marked THRUST on one face, and that face is the thrust-carrying face. Carton printed 3MM214WI CR; outer ring stamped FAFNIR, THRUST and MADE IN U.S.A.

Interchange guidance

Base Number: 7214. MPN Variants: 3MM214WICR, 3MM214WI CR, 3MM-214-WI-CR, 3-MM-214-WI-CR, 3MM 214 WI CR, 3MM214WI, 7214AC. Same-envelope 25° super precision equivalents are written SKF 7214 ACD/P4A, FAG B7214-E-T-P4S and NSK 7214A5. Cage material and precision class vary between makers inside those designations. The line passed from Fafnir to Torrington to Timken, and Timken lists the 3MM214WI CR family today.