NSK7910A5TRDULP4YAngular Contact Ball Bearing – 50 mm ID, 72 mm OD, 12 mm Width, 25 Degree Contact Angle, Outer-Ring Guided Phenolic Cage, Light Preload

Product Description

What this part is

NSK 7910A5TRDULP4Y super-precision angular contact ball bearings, supplied as a duplex pair at light preload. Series: 79 (ISO dimension series 19, thin section). Bore: 50 mm. Outside Diameter: 72 mm. Width: 12 mm per bearing. Contact Angle: 25°. Cage Material: Laminated phenolic. Cage Type: Outer-ring guided. Preload: Light. Rolling Elements: Ball. Bore Type: Straight.

Decoding the designation

7910 — NSK’s number for the 79 series, 50 x 72 x 12 mm. The same size is catalogued elsewhere as 71910.

A5 — 25° contact angle.

TR — outer-ring-guided laminated phenolic cage, rated to 120 °C.

DU — duplex pair.

L — light preload class.

P4Y — NSK special precision class, held tighter than P4.

What these specs mean in practice

Dynamic Load Rating: 20.1 kN per bearing. Static Load Rating: 14.2 kN per bearing. Limiting Speed: 16,400 r/min on grease and 24,600 r/min on oil-air, single bearing. Contact Angle: 25°. Effective load centre a: 20.2 mm. Chamfer r min: 0.6 mm. Chamfer r1 min: 0.3 mm. Mass: 0.132 kg per bearing.

The 79 series is the thin-section spindle family: a 50 mm bore inside a 72 mm outside diameter only 12 mm wide, which is what fits a grinding head or a rotary table where the shaft is large and the housing wall is not. A 25° contact angle steepens the load path, so the pair carries more thrust and more axial stiffness than a 15° equivalent, and gives up some top speed for it. The phenolic cage rides on the outer ring land, runs light and quiet, and tolerates the thin oil films of an oil-air feed.

Mounting data

Shaft abutment diameter da: 55 mm minimum. Housing abutment diameter Da: 67 mm maximum. Second housing abutment diameter Db: 69.5 mm maximum. Shaft or housing fillet radius ra: 0.6 mm maximum. Second fillet radius rb: 0.3 mm maximum.

Quantity and configuration

Unit Quantity: 2 Pcs. A duplex pair ground for light preload, clamping up against a plain spacer.

Interchange guidance

Equivalent 25° executions on the same envelope: SKF 71910 ACD/P4ADGA, FAG B71910-E-T-P4S, RHP 7910A5TRDULP4. Searchable variants of the designation: 7910A5TRDULP4Y, 7910-A5-TR-DUL-P4Y, 7910 A5 TR DUL P4Y, 71910, 7910A5. A 7910C on the same envelope carries a 15° angle, which raises the speed rating and lowers the thrust capacity.