Fafnir2MM205WI-SUMSuper-Precision Angular Contact Ball Bearing – 25 mm ID, 52 mm OD, 15 mm Width, 15° Contact Angle, Medium Preload, ABEC 7/9

Product Description

What this part is

Fafnir 2MM205WI-SUM super-precision angular contact ball bearing on the ISO 7205 C envelope. Bore: 25 mm. Outside Diameter: 52 mm. Overall Width: 15 mm. Contact Angle: 15°. Precision Class: P4S (ABEC 7/9). Cage Material: Phenolic. Cage Type: Machined. Preload: Medium. Mounting Arrangement: Single universal. Bore Type: Straight. Closure Type: Open. Number Of Rows: 1. Rolling Elements: Balls. Bearing Material: Bearing steel. Series: 200 (ISO dimension series 02). Country of Origin: United States.

Decoding the designation

The 2MM prefix marks the Timken Fafnir super-precision range at a 15° contact angle, and it carries P4S tolerances. WI places the bearing in the ISO 200 dimension series. SUM is the grouping and preload code: SU for a single universally ground bearing, M for medium preload.

What these specs mean in practice

Dynamic Load Rating: 18.5 kN (4,150 lbf). Static Load Rating: 8.9 kN (2,000 lbf). Limiting Speed: 27,100 rpm. Maximum Operating Temperature: 120 °C. Minimum Operating Temperature: -30 °C. Item Weight: 0.28 lb. A 15° contact angle carries more radial load and runs faster than a 25° or 40° angle, at lower thrust capacity, which is what suits it to machine-tool spindles and high-speed pump and gearbox positions. The machined phenolic cage is light and outer-ring guided, so it adds little inertia at speed and runs quietly. P4S tolerances hold bore and raceway runout to a few microns, giving closer shaft location and lower running vibration than a standard-class bearing.

Quantity and configuration

Unit Quantity: 1 Pc. Universal grinding means two or more of these can be stacked back-to-back, face-to-face or in tandem and reach the rated medium preload when clamped, with no ground spacer.

Fitting notes

Bore Type: Straight, for an interference fit on the shaft with the inner ring rotating. Closure Type: Open, so lubricant is supplied from the housing. Harmonization Code: 8482.10.50.

Interchange guidance

Cross-Reference 1: SKF 7205 CD/P4ADGB, the same envelope at the same 15° contact angle and medium preload. Searchable designation forms: 2MM205WI-SUM, 2MM-205-WI-SUM, 2MM205WISUM, 2MM205WI, 2MM205WIDUM, B7205C.T.P4.DUM, 7205C and 7205-C.