Fafnir3MM308WI DUHAngular Contact Ball Bearing — 40 mm ID, 90 mm OD, 23 mm Width, 25° Contact Angle, Heavy Preload, ABEC 7

Product Description

What this part is:

Fafnir 3MM308WI-CR-DUH super-precision angular contact ball bearings, 300WI spindle series, supplied as a universally ground duplex pair (2 Pcs). Envelope per bearing: 40 mm bore, 90 mm outside diameter, 23 mm width. 25° contact angle, heavy preload, phenolic cage.

Decoding the designation:

3MM — 25° contact angle in the Fafnir super-precision spindle range.

MM — super-precision spindle execution, Precision Class ABEC 7 / P4.

308 — the 300WI medium dimension series, ISO 7308 envelope, 40 mm bore.

WI — low shoulder on both rings.

CR — phenolic outer land riding cage, in Timken’s own wording.

DU — duplex, a factory-matched pair ground to run together.

H — heavy preload.

Specifications:

Series: 300WI. Base Number: 3MM308WI. Bore Diameter: 40 mm. Outside Diameter: 90 mm. Overall Width: 23 mm per bearing. Total Width: 46 mm for the pair. Bore Type: Straight. Closure Type: Open. Rolling Elements: Ball. Number Of Rows: 1 per bearing. Bearing Material: Chrome steel. Design Units: Metric.

Contact Angle: 25°. Precision Class: ABEC 7 / P4. Preload: Heavy.

Dynamic Load Rating (C1): 57,500 N per bearing. Dynamic Load Rating (C1 ISO, per row): 52,300 N. Static Load Rating: 33,800 N.

Limiting Speed: 15,200 rpm grease; 30,400 rpm oil. Lubricant: grease or oil.

Cage Material: Phenolic. Cage Type: CR – Phenolic outer land riding cage.

Unit Quantity: 2 Pcs. Mounting Arrangement: Duplex, universally ground.

Dimensions and mounting:

Maximum Shaft Fillet Radius: 1.5 mm. Outer Ring To Clear Radius: 1.5 mm. Shaft Backing Shoulder Diameter: 49.3 mm. Housing Backing Shoulder Diameter: 81.3 mm. Universal grinding allows back-to-back, face-to-face or tandem mounting at the published heavy preload.

Compatibility and replacement:

Timken world part number: 7308E-T-DUH-P4. SKF 7308 ACD/P4ADGC. FAG B7308-E-T-P4S-DUH. NSK 7308A5TRDUHP4. RHP B7308X3TDUHP4. These are 40 x 90 x 23 mm at a 25° contact angle, heavy-preload matched pairs. 7308-A is a related size at 30° in the NSK scheme.

Frequently asked questions:

What are the dimensions of the Fafnir 3MM308WI-CR-DUH?

Bore Diameter: 40 mm. Outside Diameter: 90 mm. Overall Width: 23 mm per bearing, 46 mm for the pair.

What contact angle and preload does it have?

Contact Angle: 25°. Preload: Heavy (DUH).

What are the load ratings?

Dynamic Load Rating (C1): 57,500 N per bearing. Dynamic Load Rating (C1 ISO, per row): 52,300 N. Static Load Rating: 33,800 N.