NSK7208A5-DULAngular Contact Ball Bearing Matched Pair – Straight Bore, 40 mm ID, 80 mm OD, 18 mm Width, Open, 25° Contact Angle, Light Preload, 2 Pcs.

Product Description

What this part is

NSK 7208A5TYDULPA1 angular contact ball bearings, supplied as a matched pair. 40 mm straight bore, 80 mm outside diameter, 18 mm width per bearing. Open on both faces, polyamide resin ball-guided cage, 25° contact angle, light preload. The carton also carries 7208A5-DUL, 7208 E DUL and 7208 ACD DGA.

Decoding the designation

7 marks NSK’s high-accuracy angular contact standard series and 2 the 02 dimension series. The bore number 08 multiplied by five gives the 40 mm bore. A5 is NSK’s code for a 25° contact angle. TY is the polyamide resin ball-guided cage. DU is the universal pairing of two rows and L is light preload.

What these specs mean in practice

A single-row angular contact bearing takes thrust in one direction, which is why these are supplied and mounted as a pair: back-to-back or face-to-face, the pair carries thrust both ways and locates the shaft axially in both senses. The 25° contact angle gives more thrust capacity and axial stiffness than a 15° bearing of the same envelope, trading a little speed for it. Light preload removes internal play while keeping running torque and heat generation down. The polyamide ball-guided cage is light and quiet, with a 120°C ceiling.

Quantity and configuration

2 Pcs, one matched pair. The rings are ground so the light preload comes up on assembly with no shims, and the arrangement mark on the outer ring faces sets the orientation. Load ratings and limiting speed listed are per bearing.

Fitting notes

Assembly is dry and clean, with an interference fit on the inner rings and a location fit in the housing bore. Both rings are clamped fully home against the shaft shoulder and the housing shoulder so the ground offset closes and the preload reaches its design value. Because the cage is polyamide, heat for mounting is applied to the shaft rather than the bearing.

Interchange guidance

Another maker’s 40 x 80 x 18 mm 25° matched pair at light preload substitutes directly. A single universal bearing of the same size is a related size rather than an interchange: it is ground for field matching and does not carry a duplex offset. A 15° bearing in this envelope is also a related size, since the thrust capacity and speed behaviour differ.