NSK7209A5-DULAngular Contact Ball Bearing – 45 mm ID, 85 mm OD, 19 mm Width, Straight Bore, Open, 25 Degree, Light Preload Universal Duplex Set of 2

Product Description

What this part is
NSK 7209A5-DUL angular contact ball bearing, supplied as a universally ground duplex set of two. Brand: NSK. Base Number: 7209. Series: 7200, ISO 72 medium series. Open on both faces, high carbon chrome steel rings and balls.

Dimensions and mass (per single bearing)
Bore Diameter: 45 mm. Outside Diameter: 85 mm. Width: 19 mm. Total Mounted Width of the pair: 38 mm. Mass: 0.402 kg. Bore Type: Straight. Seal Type: Open. Material: High Carbon Chrome Steel.

Load ratings (per single bearing)
Basic Dynamic Load Rating (Cr): 49.0 kN. Basic Static Load Rating (C0r): 27.6 kN. Permissible Axial Load (Pa): 23.3 kN. Contact Angle: 25 deg (NSK A5 execution).

Mounting data
Contact Point Distance (a): 24.7 mm. Minimum Shaft Shoulder Diameter (da min): 52 mm. Maximum Housing Shoulder Diameter (Da max): 78 mm. Maximum Housing Bore Shoulder (Db max): 80 mm. Chamfer Dimension (r min): 1.1 mm. Chamfer Dimension (r1 min): 0.6 mm.

Decoding the designation
7209 gives the ISO 72 medium series with bore code 09 for the 45 mm bore. A5 is the NSK code for a 25 deg contact angle. DUL is a universal duplex pairing at light preload.

What these specs mean in practice
A 25 deg contact angle carries more thrust than a 15 deg bearing in the same envelope, so it suits a shaft position with meaningful axial load. Light preload keeps running heat and friction down relative to a medium or heavy preload, at some cost in axial stiffness.

Configuration
Two bearings, universally ground so the pair can be arranged back-to-back, face-to-face or in tandem, developing light preload in any of those arrangements. Rolling Elements: Balls. Number of Rows: 1 per bearing, 2 rows in the mounted set. Unit Quantity: 2 Pcs.

Interchange guidance
Same-specification equivalents at 25 deg and light preload in this envelope are the SKF 7209 ACD/P4A DGA and the Fafnir 3MM209WI-DUL. A 7209A5-DUM is the same pair at medium preload and a 7209C-DUL is the 15 deg execution, so both are related sizes rather than interchanges.