Fafnir3MM9110WICRDUHAngular Contact Ball Bearing – 50 mm ID, 80 mm OD, 16 mm Width, Open, 25°, Heavy Preload, Universal Duplex Pair

Product Description

What this part is

Fafnir 3MM9110WICR-DUH super-precision angular contact ball bearing, supplied as a universally ground matched duplex pair. Bore 50 mm, outside diameter 80 mm, width 16 mm per bearing, 32 mm across the pair. ISO equivalent size 7010. Fafnir is a Timken brand.

Decoding the designation

The 3MM prefix gives a 25° contact angle, and the MM series is built to P4S, equivalent to ABEC 7 dimensional tolerances with ABEC 9 running accuracy. 9110 is the Fafnir series code for the ISO 7010 size. WI is the super-precision angular contact execution. CR is the phenolic outer-land-riding cage. DUH is a duplex universal set at heavy preload.

What these specs mean in practice

The 25° contact angle is the thrust-biased option in this family, carrying more axial load and giving higher axial rigidity than a 15° bearing of the same envelope. Timken lists the 3MM series for thrust-dominated spindle work such as vertical rotary surface grinders, disc grinders and heavy-duty lathe thrust positions. Heavy preload maximises stiffness and holds position under reversing load, at the cost of more heat and a lower speed ceiling than a light-preload set. Dynamic capacity is 21.8 kN, static capacity 17 kN, limiting speed 18,000 rpm, and the phenolic cage sets the upper temperature limit at 121 °C.

Quantity and configuration

Two bearings, matched as one set, with steel balls and a phenolic outer-land-riding cage. Universal grinding allows back-to-back, face-to-face or tandem arrangement, with preload established as the ground ring faces are clamped together.

Preload and clearance

Heavy preload, ground into the ring faces. A preloaded matched pair has no operating radial internal clearance, so clearance classes such as CN do not apply.

Fitting notes

Each outer ring carries a V mark across the outside diameter; the marks are aligned to hold the intended arrangement. Shaft and housing seats are held to precision tolerances, and both bearings are clamped as one unit against a common shoulder. Heavy preload makes generous oil lubrication and adequate cooling important.

Interchange guidance

FAG B7010-E-T-P4S-DUH is a same-specification interchange — E on a B70 designation is a 25° contact angle, T the phenolic cage, DUH the duplex universal heavy-preload arrangement. NSK 7010A5TYNDUHP4 matches size, angle and arrangement with a polyamide ball-guided cage. 3MM9110WICR-DUL and 3MM9110WICR-DUM are the same bearing at light and medium preload, so they are related preload classes rather than interchanges. 2MM9110WI-DUH is the same envelope and preload at a 15° contact angle.