Fafnir2MMV99104WN-DULAngular Contact Ball Bearing — 20 mm ID, 42 mm OD, 12 mm Width, Phenolic Outer Land Riding Cage, Light Preload

Product Description

What this part is

Fafnir 2MMV99104WN-DUL, a super-precision spindle angular contact ball bearing from Timken’s Fafnir range. Bore: 20 mm. Outside Diameter: 42 mm. Bearing Width: 12 mm per bearing. Total Width: 24 mm across the set. Contact Angle: 15°. Precision Class: ABEC 7/9 (ISO P4S). Cage Type: CR, phenolic outer land riding. Cage Material: phenolic. Preload: light. Rolling Elements: steel balls. Number of Rows: 1 per bearing. Manufacturer Part Number: 2MMV99104WN-DUL.

Decoding the designation

2MMV — Fafnir super-precision spindle execution at a 15° contact angle, ground to ABEC 7/9 (ISO P4S) tolerance.

9104 — 9100WI dimension series, bore code 04. That is the ISO 7004 envelope: 20 mm bore, 42 mm outside diameter, 12 mm width per bearing.

CR — phenolic outer land riding cage, guided on the outer ring lands.

DUL — duplex, light preload. Two universally ground bearings supplied as a matched set, faces flush-ground so they close to the same preload when clamped.

What these specs mean in practice

A 15° contact angle keeps the load path close to radial, which is the high-speed build in the family. The 25° execution on the same 20 x 42 x 12 mm envelope trades that speed for thrust capacity.

The phenolic outer land riding cage is the standard cage for spindle duty. It is light, so it adds little to the ball-set inertia at high speed, it runs quiet, and the resin holds oil in its own porosity to carry lubricant to the ball pockets. Light preload sets the spindle stiffness while keeping the ball contact loads low enough that running temperature stays down.

A universally ground set is ground so that the ring faces are flush and the internal offset is identical piece to piece. That is what allows two bearings out of the same bin to be clamped together and arrive at the same preload without shimming.

Quantity and configuration

Unit Quantity: 2 Pcs. A matched duplex set of two universally ground bearings, 24 mm total width when clamped together.

Interchange guidance

Searchable variants of the number: 2MMV99104WN-DUL, 2MMV-9-9104-WN-DUL, 2MMV9 9104 WN CR DUL, 2MMV99104WNCRDUL, 9104WN, 7004C.

The 20 x 42 x 12 mm envelope is the ISO 7004 seat, so a 7004C of matching precision class occupies the same shaft and housing bore.