Fafnir2MM9308WICRTUMSuper Precision Angular Contact Ball Bearing – Straight Bore, 40 mm ID, 62 mm OD, 12 mm Width, Open, 15° Contact Angle, Universal Pairing, Medium Preload.

Product Description

What this part is

Fafnir 2MM9308WI CR TUM matched triple set of super-precision angular contact ball bearings. Bore Diameter: 40 mm. Outside Diameter: 62 mm. Overall Width: 12 mm per bearing. Contact Angle: 15°. Precision Class: ABEC 7 / P4. Unit Quantity: 3 Pcs. The envelope is the ISO 71908 size, also written 7908.

Decoding the designation

2MM — Timken/Fafnir super-precision class. ISO P4 / ABEC 7 running accuracy, with a 15° contact angle.

9308 — the ISO 71908 size: 40 mm bore, 62 mm outside diameter, 12 mm width.

WI — low shoulder on both rings, the ground duplex form.

CR — machined phenolic cage.

TUM — triple universally ground, medium preload. The three bearings are ground as one matched stack.

What these specs mean in practice

Contact Angle: 15°. A 15° angle favours speed and radial stiffness; a larger angle trades those for axial capacity.

Cage Material: Phenolic. Cage Type: Machined. A phenolic cage is light, self-lubricating and tolerant of high cage speeds.

Preload: Medium. Mounting Arrangement: Universal. Lubricant: grease or oil. Rolling Elements: Ball. Number Of Rows: 1 per bearing. Bore Type: Straight. Closure Type: Open. Bearing Material: Bearing Steel. Series: 9300. Harmonization Code: 8482.10.50.

Quantity and configuration

Unit Quantity: 3 Pcs. Arrangement / Configuration: matched triple set, universally ground, medium preload. Any three universally ground bearings of the same execution stack in back-to-back, face-to-face or tandem order.

Interchange guidance

The 40 x 62 x 12 mm envelope is the ISO 71908 size at a 15° contact angle, written 71908 by SKF, FAG and SNR and 7908 by NSK, NTN, RHP and Koyo. Those crosses are on the single-bearing envelope; this listing is a factory-matched three-bearing stack.