Fafnir2MM216WIDULSuper Precision Angular Contact Ball Bearing 80x140x26 mm 15 Degree Contact Angle Phenolic Cage Universally Ground Light Preload Single Bearing

Product Description

What this part is

A single-row super precision angular contact ball bearing in the 7216 envelope — 80 mm bore, 140 mm outside diameter, 26 mm width. It is a spindle-grade bearing, not a general-purpose one: the grinding tolerances, the phenolic cage and the controlled preload all exist to support a rotating tool or workhead at speed with predictable axial position.

Decoding the designation

2MM – Timken/Fafnir code for a 15° contact angle. The MM prefix also carries the P4S precision level (not plain P4).
216 – 200-series envelope, 80 mm bore.
WI – Fafnir super-precision series code.
CR – phenolic cage, outer-land riding.
SU – single bearing, universally ground; L – light preload. So SUL = one universally ground bearing set for light preload.

Correcting the source data

The old listing title carried both -SUL and -CR-DUL. Those cannot both be true. SU means a single universally ground bearing and DU means a factory-matched duplex pair — a designation asserting both is a transcription error. On-hand quantity is 1, which agrees with the single reading, so this is published as 2MM216WI-SUL, one bearing. The DUL form is retained only as a search term so buyers arriving from the old number still find the part. The unsupported “USA” origin claim has also been removed from the prose; the word stays in the title as a search term only, because no carton marking or manufacturer publication has been verified.

What these specs mean in practice

A 15° contact angle is the high-speed, low-axial-load end of the angular contact range. Compared with a 25° bearing it generates less heat and tolerates higher speed, but carries noticeably less thrust and gives less axial stiffness — which is why 15° bearings dominate high-rpm grinding and light-cut milling spindles while 25° bearings go into heavier boring and drilling work. The phenolic outer-land-riding cage is light and self-lubricating, well suited to oil-mist and grease-for-life spindles, but it is less tolerant of contamination and of high temperature than a machined bronze cage. Universal grinding means this bearing can be stacked back-to-back, face-to-face or in tandem with another universally ground bearing of the same designation and preload class, and the preload comes out correct without shims.

Published ratings and mounting data

Dynamic and static load ratings, limiting speed and the preload force in newtons are deliberately left blank. Timken does not publish an open catalogue table for this exact Fafnir WI-series suffix combination, and the figures that circulate on distributor mirrors belong to adjacent designations. Borrowing a 7216 P4 number for a P4S bearing would misstate both the rating and the speed capability. Request the values against the full designation from Timken if your calculation depends on them.

Quantity and configuration

One bearing. It is universally ground, so it can be paired later, but it is supplied and priced as a single piece and is not a matched set.

Fitting notes

Never mix preload classes in a stack — an L bearing next to an M bearing produces an indeterminate preload and usually a hot spindle. Mount by the marked faces, keep the bearing in its wrapper until the shaft and housing are clean and measured, and do not spin it dry. Confirm the housing and shaft fits against the spindle drawing rather than against general-purpose tables; super precision bearings assume tighter seats.

Interchange guidance

Fafnir is now part of Timken, so current enquiries route through Timken. The ISO base number is 7216 and the 15° equivalent in other super precision lines is a 7216 C-class bearing, but precision grade, cage and preload must match before any substitution — same envelope does not mean same bearing.