Fafnir2MM214WI-SUMAngular Contact Ball Bearing – 70 mm ID, 125 mm OD, 24 mm Width, Open, 15° Contact Angle, Medium Preload.

Product Description

What this part is

Fafnir 2MM214WI-SUM super-precision angular contact ball bearing. Bore: 70 mm. Outside diameter: 125 mm. Width: 24 mm. Series: 200 (ISO 72xx medium series). Single row, open on both faces. Contact Angle: 15°. The ISO base number for this envelope is 7214.

Decoding the designation

2MM: 15° contact angle. MM prefix: P4S tolerance, ABEC 7 running accuracy with ABEC 9 dimensional accuracy. WI: super-precision spindle execution. SU: single bearing, universally ground so any two pieces stack back-to-back, face-to-face or in tandem and reach the marked preload when clamped. M: medium preload. Precision Class: P4S (ABEC 7/9). Country of origin on this item: United States.

Published ratings

Dynamic Load Rating: 79 kN. Static Load Rating: 72 kN. Limiting Speed: 12,000 rpm. Operating temperature range: −30 °C to 120 °C. Running accuracy, radial and axial runout: P4. Item weight: 2.50 lb.

What these specs mean in practice

The 72xx medium series carries a heavier ball complement than a 70xx or 719xx of the same bore, so a 7214 envelope buys load capacity at the cost of top speed. A 15° contact angle then favours speed and radial stiffness over thrust capacity. Medium preload sits one step up the ladder from light: it raises axial and radial stiffness, holds position better under interrupted cut, and runs warmer, so the practical speed ceiling drops relative to a light-preload set. The machined phenolic cage is light, self-lubricating and quiet, and 120 °C is the phenolic material limit.

Quantity and configuration

One bearing, universally matchable. Unit Quantity: 1 Pc. The carton also carries the DUM duplex marking, which is the factory pairing designation for this execution and is a useful search term.

Interchange guidance

Same-envelope 15° super-precision equivalents: SKF 7214 CD/P4A, and in medium-preload universally matchable form SKF 7214 CD/P4ADGB; RHP 7214CTDUMP4; NSK 7214C. A 7214 ACD, 7214A5 or RHP 7214E is a related size on the same 70 x 125 x 24 mm envelope at a 25° contact angle.