Fafnir3MM209WIDULSuper-Precision Angular Contact Ball Bearing Pair – 45 mm Bore, 85 mm OD, 19 mm Width, 25°, Light Preload

Product Description

What this part is

Fafnir 3MM209WICRDUL, a super-precision angular contact ball bearing supplied as a universally ground duplex pair. Bore Diameter: 45 mm. Outside Diameter: 85 mm. Overall Width: 19 mm per bearing. Total Width: 38 mm mounted as a pair. Contact Angle: 25°. Rolling Elements: Ball. Number Of Rows: 1 per bearing. Bore Type: Straight. Closure Type: Open. Cage Material: Phenolic. Precision Class: ABEC 7/9 / P4S. Preload: Light. Series: 200WI. Base Number: 3MM209WI. GTIN: 087796074453.

Decoding the designation

3MM — Fafnir super-precision spindle range at a 25° contact angle, ground to ABEC 7/9 (P4S) tolerances.

209 — 200 medium dimension series, bore code 09, which maps to the ISO 7209 envelope: 45 mm bore, 85 mm outside diameter, 19 mm width.

WI — low shoulder on both rings.

CR — phenolic cage.

DUL — duplex pair, universally ground, light preload. Either face can be brought together, so the pair mounts back-to-back, face-to-face or in tandem.

What these specs mean in practice

Dynamic Load Rating: 43,100 N per bearing. Static Load Rating: 27,600 N per bearing. Limiting Speed: 17,200 rpm grease; 31,600 rpm oil. Item Weight: 0.816 kg (1.80 lb) for the pair. Internal Clearance: N/A — a preloaded set is clamped to a defined stiffness rather than run to a clearance. The 25° contact angle carries more thrust and locates the shaft more firmly than the 15° execution on the same envelope, at 31,600 rpm on oil against 35,000 rpm for the 2MM form. Light preload keeps running heat down.

Mounting data

Shaft Backing Shoulder Diameter: 52.3 mm. Housing Backing Shoulder Diameter: 78.2 mm. Maximum Housing Fillet Radius: 1 mm (0.039 in) — the largest housing corner radius the bearing corners will clear.

Quantity and configuration

Unit Quantity: 2 Pcs. One universally ground duplex pair. The 19 mm figure is the width of a single bearing; the pair occupies 38 mm of shaft length when clamped together.

Interchange guidance

Direct super-precision equivalents on the 7209 envelope at 25° with light preload: FAG B7209-E-T-P4S-UL, SKF 7209 ACD/P4ADGA, NSK 7209A5TRDULP4, NTN 7209UAD/GNP4, RHP 7209ETDULP4 and Koyo 7209A5 P4 DUL. SNR 7209HG1DUJ74 is the equivalent French execution. MRC 7209 is a related size only: MRC’s plain 7000 series runs a 29° contact angle. Searchable variants include 3MM209WIDUL, 3MM-209-WI-DUL, 3 MM 209 WI CR DUL, 3MM209WICRDUL, 7209A, 7209A5 and 7209ACD.