Fafnir2MM9124WI-QNTAngular Contact Ball Bearing – Straight Bore, 120 mm ID, 180 mm OD, 28 mm Width, Open, 15° Contact Angle, ABEC 7 / P4

Product Description

What this part is

Fafnir 2MM9124WI CR super-precision angular contact ball bearing, one bearing from a factory four-bearing set. Bore Diameter: 120 mm. Outside Diameter: 180 mm. Overall Width: 28 mm. Contact Angle: 15°. Precision Class: ABEC 7 / P4. The envelope is the ISO 7024 size.

Decoding the designation

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

9124 — the ISO 7024 size: 120 mm bore, 180 mm outside diameter, 28 mm width.

WI — low shoulder on both rings. This is the ground duplex form, so bearings of the same execution stack as a matched set.

CR — machined phenolic cage.

QNT-1/4SET — one bearing from a factory four-bearing set.

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.

Rolling Elements: Ball. Number Of Rows: 1. Bore Type: Straight. Closure Type: Open. Bearing Material: Bearing Steel. Series: 9100. Harmonization Code: 8482.10.50.

Quantity and configuration

Unit Quantity: 1 Pc. One bearing from a factory four-bearing set, ground for duplex stacking with bearings of the same execution.

Interchange guidance

The 120 x 180 x 28 mm envelope is the ISO 7024 size at a 15° contact angle, carried by SKF, FAG, NSK, NTN, RHP, Koyo, MRC and SNR under the same 7024 base number. Suffix executions differ between makers.