Fafnir2MM209WIDULSuper-Precision Angular Contact Ball Bearing Matched Pair – Straight Bore, 45 mm ID, 85 mm OD, 19 mm Width, Open, 15° Contact Angle, Light Preload, Phenolic Cage.

Product Description

What this part is

Fafnir 2MM209WI-DUL matched duplex pair of super-precision angular contact ball bearings, 200WI spindle series, built by The Timken Company. Part Number: 2MM209WI-DUL. World Part Number: 7209C-T-P4S-DUL. Bore: 45 mm. Outside Diameter: 85 mm. Bearing Width: 19 mm per bearing. Total Width: 38 mm for the mounted pair. Design Units: Metric. Number Of Rows: 1 per bearing. Rolling Elements: Steel balls. Bore Type: Straight. Closure Type: Open. Bearing Material: Chrome bearing steel.

Decoding the designation

2MM — 15° contact angle, super-precision execution.

209WI — 200WI series on the ISO 7209 envelope, 45 x 85 x 19 mm, with a low shoulder on both rings.

CR — phenolic outer-land-riding cage.

DUL — matched duplex pair, universally ground, at light preload.

Published ratings

Dynamic Radial Load Rating – 1M Revs (C1): 45,200 N (10,200 lbf) per bearing. C1 ISO Dynamic Radial Rating, per row: 41,100 N (9,270 lbf) per bearing. Static Radial Load Rating (C0): 28,800 N (6,470 lbf) per bearing. Limiting Speed – Grease: 17,500 rpm. Limiting Speed – Oil: 35,000 rpm. Contact Angle: 15°. Precision Rating: ISO P4S (ABEC 7/9). Precision Class: ABEC 7/9. Preload: Light. Cage Type: CR – phenolic outer-land-riding. Cage Material: Phenolic. Lubricant: grease or oil.

Mounting data

Maximum shaft fillet radius: 1 mm (0.039 in). Maximum housing fillet radius: 1 mm (0.039 in). Shaft Backing Shoulder Diameter: 52.3 mm (2.060 in). Housing Backing Shoulder Diameter: 78.2 mm (3.080 in).

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness over thrust capacity, which is why it is the usual choice at the rear of a machine tool spindle. The phenolic cage is guided on the outer ring land, so it stays centred at high speed and holds lubricant against the ball pockets. Internal Clearance: N/A — the pair is set by preload rather than by a clearance class. Running Accuracy – Radial And Axial Runout: High precision.

Quantity and configuration

Unit Quantity: 2 Pcs. Arrangement / Configuration: matched duplex pair, universally ground. Mounting Arrangement: universal. The two bearings are ground as a matched set, so mounting them against one another produces the light preload class directly, with no shims and no regrinding. Universal grinding also allows a back-to-back, face-to-face or tandem stack.

Interchange guidance

Base Number: 2MM209WI. Series: 200WI. Harmonization Code: 8482.10.50. Cross-references: SKF 7209 CD/P4ADGA, NSK 7209CTRDULP4Y, FAG B7209-C-T-P4S-DUL, Timken 7209C. Each is a 15° light-preload duplex set on the 45 x 85 x 19 mm envelope. Searchable forms: 2MM209WI-DUL, 2MM209WIDUL, 2MM 209 WI DUL, 2-MM-209-WI-CR-DUL, 7209C T P4S, 7209-C, 2MM209WI.