Fafnir2MM9106WICRTULSuper Precision Angular Contact Ball Bearing Triplex Set – Straight Bore, 30 mm ID, 55 mm OD, 13 mm Width, Open, 15° Contact Angle, Light Preload

Product Description

What this part is

A universally ground triplex set of three Fafnir 2MM-9106-WI-CR-TUL super-precision angular contact ball bearings. Single row each, 30 mm bore, 55 mm outside diameter, 13 mm width, open on both faces, with a machined phenolic cage riding on the outer ring land.

Decoding the designation

In the Fafnir super-precision scheme the 2MM prefix denotes a 15° contact angle and carries class P4S, meaning ABEC 7 tolerances with ABEC 9 running accuracy. The leading 9 places the bearing in the ISO 7000 light series, so 9106 is the ISO 7006 size, 30 x 55 x 13 mm. WI marks the spindle bearing range, CR the phenolic outer-ring-land-riding cage, and TUL a triplex universally ground set at light preload.

What these specs mean in practice

Each bearing carries a basic dynamic radial rating of 16.8 kN and a static radial rating of 10.3 kN, with a limiting speed of 25,500 rpm. A 15° contact angle favours speed and radial stiffness over thrust capacity. A triplex set gives roughly half again the load capacity and stiffness of a duplex pair in the same bore, which is why it appears at the drive end of loaded grinding and milling spindles. Light preload keeps added friction and heat to the minimum of the preload classes.

Quantity and configuration

Three pieces, one factory-matched triplex set, 39 mm total width. Universal grinding lets the three be arranged as a tandem pair against a single, or all three in tandem, with the light preload arising when the rings are clamped together.

Fitting notes

The marked ring faces go together in the factory-ground orientation and the whole stack clamps square against a rigid shoulder so the preload lands as designed. Clamping load passes through the rings. Operating range for the phenolic cage is –40 °C to 120 °C.

Interchange guidance

Equivalents at the same size, angle, cage, class and preload include FAG B7006-C-T-P4S-TUL, SKF 7006 CD/P4ATBTA, NSK 7006CTRTULP4 and RHP 7006CTTULP4. The 3MM9106WI variant is the same 30 x 55 x 13 mm envelope at a 25° angle, and the 2MM9106WI-DUL is the two-piece duplex version of this set; both are related sizes rather than interchanges.