Fafnir2MM9509WICRDULSuper Precision Angular Contact Ball Bearing Matched Duplex Pair 45 x 80 x 18 mm 15 Degree ABEC 7 Light Preload

Product Description

What this part is

A matched duplex pair of super-precision angular contact ball bearings in the Fafnir 9500WI spindle series. Brand: Fafnir (Timken). Part Number: 2MM9509WI-DUL. Bearing Type: angular contact ball bearing, super-precision spindle. Series: 9500WI. Base Number: 9509. Bore: 45 mm (1.7717 in). Outside Diameter: 80 mm (3.1496 in). Overall Width: 18 mm (0.7087 in) per bearing. Total Width: 36 mm (1.4173 in) for the duplex pair.

Decoding the designation

2MM — 15° contact angle, Fafnir super-precision spindle bearing. 9509 — 9500 dimension series, bore code 09, giving a 45 mm bore. WI — spindle angular contact ball bearing, universally ground faces. CR — phenolic cage riding on the outer ring land. DU — duplex, a factory-matched set of two. L — light preload.

The MM prefix on a Fafnir spindle bearing carries P4S tolerances — ABEC 7 dimensional accuracy with ABEC 9 running accuracy.

Published specifications

Contact Angle: 15°. Precision Class: ABEC 7 / ISO P4S. Precision Rating: ABEC 7 / P4. Preload: Light (L). Number Of Rows: 1 per bearing. Cage Material: Phenolic (fabric-reinforced laminate). Cage Type: Outer-land-riding. Rolling Elements: Steel balls. Closure Type: Open, both faces. Bore Type: Straight. Internal Clearance: CN. Design Units: Metric.

Dynamic Load Rating: 29 kN. Static Load Rating: 16 kN. Limiting Speed: 20000 rpm. Maximum Temperature: 120 °C. Minimum Temperature: −40 °C. Item Weight: 0.90 lbs. Material: Bearing Steel. Harmonization Code: 8482.10.5028. UNSPSC: 31171504.

What these specs mean in practice

A 15° contact angle biases the bearing toward speed and radial rigidity, and carries less thrust than a 25° bearing in the same envelope. Light preload keeps contact loads and heat generation low, which suits high-speed spindles where thermal growth rather than stiffness sets the limit. The 9500WI series sits between the ISO 7000 and 7200 envelopes, giving a heavier ball complement than a 9100WI of the same bore in a smaller outside diameter than a 200WI. Phenolic places the working temperature ceiling near 120 °C.

Quantity and configuration

Matched duplex pair, 2 Pcs. Unit Quantity: 2 Pcs. Mounting Arrangement: duplex, matched set of 2. Arrangement / Configuration: duplex matched pair (DU). The two bearings are ground as a set, and the pair carries the light preload as supplied.

Interchange guidance

The 9500WI envelope is specific to the Fafnir series and has no ISO 7000-series counterpart at 45 × 80 × 18 mm, so a 7009 or a 7209 is a related size rather than an interchange. The 3MM9509WI is a 25° bearing in the same envelope, and the DUM and DUH variants differ in preload — also related sizes. Cross-references: Timken 2MM9509WI-DUL, NSK 7009CTYNDULP4, FAG B7009-C-T-P4S-DUL, SKF 7009 CD/P4ADGA.