Fafnir3MM9310WI-DUMSuper-Precision Angular Contact Ball Bearing – 50 mm ID, 72 mm OD, 12 mm Width, Open, 25 Degree, Medium Preload Universal Duplex Set of 2

Product Description

What this part is:

Fafnir 3MM9310WI-DUM is a matched universal duplex set of two super precision angular contact ball bearings (DUM, medium preload), single row each, open, with a machined phenolic cage. Each bearing: 50 mm bore, 72 mm outside diameter, 12 mm width; stacked width across the pair 24 mm. Fafnir ultra-light 9300WI series, ISO 71910 envelope, 25° contact angle. Unit Quantity: 2 Pcs.

Decoding the designation:

3MM — Fafnir super precision series, 25° contact angle.

MM — P4 precision class (ABEC 7).

9310 — Fafnir ultra-light 9300WI series, which maps to the ISO 719 family: 71910, 50 x 72 x 12 mm.

WI — low shoulder on both rings, the duplex form.

CR — phenolic cage.

DUM — universally ground duplex pair at medium preload.

Specifications:

Bore Diameter: 50 mm (1.9685 in). Outside Diameter: 72 mm (2.8346 in). Width: 12 mm (0.4724 in) per bearing. Total Width: 24 mm across the pair. Contact Angle: 25°. Precision Class: ABEC 7 / P4. Preload: Medium. Cage Material: Phenolic. Rolling Elements: Ball. Number Of Rows: 1 per bearing. Closure Type: Open. Bore Type: Straight. Item Weight: 0.136 kg (0.30 lb) per bearing. Maximum shaft or housing fillet radius: 0.6 mm (0.024 in). Unit Quantity: 2 Pcs. Harmonization Code: 8482.10.50.28.

Dimensions and mounting:

The rings are ground as a matched unit, so the pair can be arranged back-to-back, face-to-face or in tandem and develops medium preload from the ground ring offset. Straight bore, open on both faces.

Compatibility and replacement:

Same 71910 envelope at 25°: FAG 71910-E-T-P4S-DUM, SKF 71910 ACD/P4ADGB and NSK 7910A5TYNDUMP4 (polyamide cage). Related Fafnir sets: 2MM9310WI-DUM is 15°, 3MM9310WI-DUL is light preload. Carton forms: 71910 E T DUM P4, 7910ACD, 7910A5.

Frequently asked questions:

What are the dimensions of the Fafnir 3MM9310WI-DUM?

50 mm bore, 72 mm outside diameter and 12 mm width per bearing; the pair stacks to 24 mm.

What is the contact angle of the 3MM9310WI-DUM?

25°. The 3MM prefix denotes 25°; the 2MM prefix is 15°.

What does DUM mean?

DUM is a universally ground duplex pair at medium preload.