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. Bore 45 mm, outside diameter 85 mm, width 19 mm per bearing, 38 mm across the mounted pair. Open on both faces, high carbon chrome steel rings and balls with a ball-guided polyamide cage.

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° contact angle. TY denotes the ball-guided polyamide cage. DUL is a universal duplex pairing at light preload.

What these specs mean in practice

A 25° contact angle carries more thrust and less speed than a 15° bearing in the same envelope, so it suits a shaft position with meaningful axial load. Dynamic load rating 35.1 kN, static load rating 25.5 kN, limiting speed 11,000 rpm. The polyamide cage is light, quiet and low friction and works well with grease, with a practical continuous temperature ceiling near 120 °C. Light preload keeps running heat and friction down relative to a medium or heavy preload, at some cost in axial stiffness.

Quantity and 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. Being preloaded, the set carries no radial internal clearance value.

Fitting notes

Straight bore on an interference fit shaft seat, outer rings located in a bored housing. The pair is ground as a matched unit and stays together. Preload comes from the ground ring offset, so no shim stack or spacer is required.

Interchange guidance

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