Fafnir2MM9104WIDUHAngular Contact Ball Bearing – 20 mm ID, 42 mm OD, 12 mm Width, Open, 15° Contact Angle, Heavy Preload, P4S (ABEC 7/9), Matched Duplex Pair

Product Description

What this part is: Fafnir 2MM9104WI-CR-DUH super-precision angular contact ball bearing, supplied as a matched duplex universal pair. Bore: 20 mm. Outside Diameter: 42 mm. Overall Width: 12 mm. Contact Angle: 15°. Series: 9100WI, the Fafnir extra-light spindle 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. Cage Material: Phenolic. Cage Type: Machined, outer-ring land-riding. Preload: Heavy. Mounting Arrangement: Duplex universal, DU. Internal Clearance: N/A, the pair is preload-set. Searchable variants of the number: 2MM9104WIDUH, 2MM-9104-WI-CR-DUH, 2MM9104WICRDUH, 2MM 9104 WI DUH. What these specs mean in practice: Dynamic Load Rating: 11.6 kN (2,600 lbf). Static Load Rating: 6 kN (1,350 lbf). Limiting Speed: 37,100 rpm. Max Temperature: 120 °C. Min Temperature: -30 °C. Item Weight: 0.32 lbs. A 15° contact angle favours speed and radial rigidity over axial capacity, which is what machine-tool spindles ask for. Heavy preload raises stiffness and holds shaft position under changing load. The phenolic cage is light and runs quietly at high speed. 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 heavy 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 outer-ring land-riding phenolic cage suits oil, oil-mist and grease lubrication at high speed. Harmonization Code: 8482.10.50. Interchange guidance: Cross-Reference: SKF 7004 CD/P4A DGC — a 15° heavy-preload universal pair on the same 20 x 42 x 12 mm envelope. ISO equivalent: 7004 C. Bearings of the same envelope built at a 25° contact angle are a related size rather than a substitution, because the thrust and speed characteristics differ.