NSK7219CTRDULP4YSuper Precision Angular Contact Bearing — 95 mm ID, 170 mm OD, 32 mm Width, Open, 15° Contact Angle, Light Preload, 2 Pcs

Product Description

What this part is

NSK 7219CTRDULP4Y, a universally matchable super-precision angular contact ball bearing, supplied as two pieces. Bore: 95 mm. Outside diameter: 170 mm. Width: 32 mm per bearing. Series: 7200. Contact angle: 15°. Precision: P4Y. Country of origin as recorded: United Kingdom.

Decoding the designation

7219 is the ISO 72 dimension series at bore code 19. C: 15° contact angle. TR: outer-ring-guided phenolic resin cage, rated to 120 °C and cleared to a 2.8 million dmn value. DU: duplex universal matching, so any two bearings of this designation pair without a spacer. L: light preload. P4Y: ISO Class 4 running accuracy with special bore and outside diameter tolerances — a tighter fit envelope than plain P4, giving closer shaft location and lower running vibration.

Ratings and speed

Basic dynamic load rating Cr: 167 kN. Basic static load rating C0r: 112 kN. Permissible axial load Pa: 76.0 kN. Limiting speed: 8,700 rpm on grease, 13,300 rpm on oil or oil-air. Effective load centre a: 33.7 mm. Axial rigidity at light preload: 130 N per micrometre. Preload force at light: 876 N.

What these specs mean in practice

A 15° contact angle favours speed and radial rigidity over thrust capacity; a 25° bearing on the same envelope carries more thrust and turns slower. The outer-ring-guided phenolic cage holds its running position at high dmn values, which is why this cage sits on machine-tool spindles where a ball-guided polyamide cage would be the grease-lubricated, lower-speed choice. Light preload keeps heat generation down while removing all axial play.

Quantity and configuration

Two pieces, universally matched, 64 mm total width as a pair. Mounted back-to-back the pair carries thrust in both directions and takes moment loads across a wide load-centre spread. Face-to-face narrows that spread and suits housings of lower accuracy. Tandem doubles thrust capacity in one direction. Measured axial clearance in a back-to-back or face-to-face pair at light preload: minus 33 micrometres.

Fitting notes

Shaft abutment diameter da: 107 mm minimum. Housing abutment Da: 158 mm maximum. Shaft fillet radius ra: 2 mm maximum. Ring chamfer r: 2.1 mm minimum. Grease charge as published: 15 g per bearing. Both faces are open.

Interchange guidance

Same-specification equivalents: SKF 7219 CD/P4ADGA and Fafnir 2MM219WI-DUL. NSK 7219CTRDUMP4Y is the same bearing at medium preload — a related size rather than a substitution, because preload sets running clearance, rigidity and heat generation.