Fafnir3MM216WIDUMAngular Contact Ball Bearing – 80 mm ID, 140 mm OD, 26 mm Width, Open, 25° Contact Angle, Medium Preload, P4S (ABEC 7/9), Matched Duplex Pair

Product Description

What this part is

Fafnir 3MM216WI-DUM super-precision angular contact ball bearing, supplied as a matched duplex universal pair. Bore: 80 mm. Outside Diameter: 140 mm. Overall Width: 26 mm. Contact Angle: 25°. Series: 200WI, the Fafnir spindle angular contact series. Bearing Type: Angular contact ball bearing. Number Of Rows: 1 per bearing. Rolling Elements: Balls. Bore Type: Straight. Closure Type: Open. Material: Bearing steel.

Decoding the designation

Precision Class: P4S, equivalent to ABEC 7/9 — the Fafnir MM super-precision grade. Running Accuracy, Radial And Axial Runout: P4. Cage Material: Phenolic. Cage Type: Machined. Preload: Medium. Mounting Arrangement: Duplex universal, DU. Internal Clearance: N/A, the pair is preload-set. Searchable variants of the number: 3MM216WIDUM, 3MM-216-WI-DUM, 3MM 216 WI DUM, 7216A.

What these specs mean in practice

Dynamic Load Rating: 85 kN. Static Load Rating: 75 kN. Limiting Speed: 9,500 rpm. Max Temperature: 120 °C. Min Temperature: -30 °C. Item Weight: 3.20 lbs. A 25° contact angle carries more thrust and less speed than a 15° bearing of the same envelope, so this execution suits spindles and screw drives that see substantial axial load. Medium preload sits between the light grade, which favours speed, and the heavy grade, which favours stiffness.

Quantity and configuration

Unit Quantity: 2 Pcs. A matched duplex universal pair. The faces are universally flush-ground, so the two bearings mount back-to-back, face-to-face or in tandem and reach the specified medium preload when clamped. Country of Origin: United States.

Fitting notes

Clamp the rings against square, flat abutments so the ground faces seat evenly and the preload comes up as specified. The machined phenolic cage suits oil, oil-mist and grease lubrication at high speed. The outer ring is plain, with no snap-ring groove.

Interchange guidance

Cross-Reference: SKF 7216 ACD/P4A DGB — a 25° medium-preload universal pair on the same 80 x 140 x 26 mm envelope. ISO equivalent: 7216 AC. Bearings of the same envelope built at a 15° contact angle are a related size rather than a substitution, because the thrust and speed characteristics differ.