Fafnir2MM213WIDUHSuper Precision Angular Contact Ball Bearing – 65 mm ID, 120 mm OD, 23 mm Width, Open, 15° Contact Angle, Phenolic Cage, Duplex Heavy Preload

Product Description

What this part is

Fafnir 2MM213WI-DUH super precision angular contact ball bearing set, built by The Timken Company. Bore Diameter: 65 mm. Outside Diameter: 120 mm. Overall Width: 23 mm per bearing. Total Width: 46 mm for the pair. Contact Angle: 15°. Precision Class: ABEC 7/9 / P4S. Preload: Heavy. Mounting Arrangement: Duplex. Number Of Rows: 1 per bearing. Rolling Elements: Ball. Bore Type: Straight. Closure Type: Open. Cage Material: Phenolic. Cage Type: Machined, outer-ring guided. Bearing Material: Chrome bearing steel. Series: 200WI. Base Number: 2MM213WI. Dynamic Load Rating: 70,400 N per bearing. Dynamic Load Rating (C1): 77,400 N for the duplex set. Static Load Rating: 54,700 N. Limiting Speed: 12,100 rpm grease; 24,200 rpm oil. Unit Quantity: 2 Pcs.

Decoding the designation

2MM — 15° contact angle in Timken’s Fafnir spindle-bearing system, and the MM prefix places the bearing in the super precision range at ISO P4S.

213 — 65 mm bore in the 200WI spindle series.

WI — low shoulder on both rings, the spindle-bearing ring form.

DUH — duplex set, heavy preload.

7213C-T-P4S-DUH — Timken’s world part number for the same bearing.

Searchable variants: 2MM213WIDUH, 2MM213WI-DUH, 2MM-213-WI-DUH, 2MM213WI DUH, 2MM213WICRDUH, 7213C-T-P4S-DUH.

What these specs mean in practice

A 15° contact angle is the shallow end of the angular contact range. It favours speed and radial stiffness over axial capacity, which is why this bearing carries a Limiting Speed of 12,100 rpm on grease and 24,200 rpm on oil. Heavy preload removes all internal play and raises axial and radial stiffness further, so the shaft holds its position under changing load; that stiffness is bought with more heat and a lower practical speed than a light-preload set. The phenolic outer-land-riding cage is light, self-lubricating and quiet, which is what makes high spindle speeds workable. ABEC 7/9 tolerances hold running accuracy tight enough for machine tool spindles, grinding heads and high-speed motorised spindles. The Dynamic Load Rating is 70,400 N for one bearing and 77,400 N for the duplex set, and the Static Load Rating is 54,700 N.

Mounting data

Straight bore, so the inner rings seat on a cylindrical spindle journal. Total Width across the pair: 46 mm. Maximum shaft fillet radius the bearing corners will clear: 1.5 mm. Outer ring to-clear radius: 1.5 mm. Shaft backing shoulder diameter: 75.7 mm. Housing backing shoulder diameter: 109.7 mm. The two bearings are ground as a matched set, so mounting them face to face against their ground faces establishes the heavy preload with no shims or spacers.

Quantity and configuration

Unit Quantity: 2 Pcs. One factory duplex pair, heavy preload, open on all faces.

Interchange guidance

Same envelope, same 15° angle and same super precision class: SKF 7213 CD/P4ADGC, FAG B7213-C-T-P4S-UH, NSK 7213CTRDUHP4, NTN 7213CDB/GHP4, Koyo 7213C-DUH-P4, RHP 7213CTDUHP4, MRC 7213KRDUH and SNR 7213HG1DU. Timken’s own world number for this bearing is 7213C-T-P4S-DUH. A 7213B or 7213WN shares the 65 x 120 x 23 mm envelope at 40° in the standard precision range, which makes it a related size rather than a substitute.