NSK7906A5TYDULP4Super-Precision Angular Contact Ball Bearing – 30 mm ID, 47 mm OD, 9 mm Width, Open, 25° Contact Angle, Light Preload, P4

Product Description

What this part is

NSK 7906A5TYSULP4 single-row super-precision angular contact ball bearing. Bore 30 mm, outside diameter 47 mm, width 9 mm. ISO 719 series, size 71906, straight bore, open both faces. Made in Japan.

Decoding the designation

Contact Angle: 25°, from the NSK A5 code. Cage Type: ball-guided, from TY. Grouping: SUL, single universally ground to light preload. Precision Class: P4, ABEC 7. Series: ISO 719. Base Number: 71906.

Published ratings

Dynamic Load Rating Cr: 9.90 kN. Static Load Rating C0r: 5.95 kN. Limiting speed: 26,000 rpm on grease, 39,000 rpm on oil-air lubrication. Effective load centre a: 13.5 mm. Mass: 0.050 kg.

What these specs mean in practice

The 719 extra-light section puts a 30 mm bore in a 47 mm outside diameter and only 9 mm of width, which buys shaft stiffness in a compact housing. A 25° contact angle carries more thrust and gives more axial stiffness than a 15° bearing of the same size, at a lower speed ceiling. Light preload keeps heat generation down while still removing play, which is why it is the usual choice for high-speed grinding and milling spindles.

Quantity and configuration

One bearing, universally ground to light preload. A universally ground bearing pairs with any other bearing of the same designation back-to-back, face-to-face or in tandem, and the preload comes out at the ground value with no spacer grinding.

Fitting notes

Shaft abutment diameter da: 32.5 mm minimum. Housing abutment diameter Da: 44.5 mm maximum. Housing fillet radius ra: 0.3 mm maximum. Chamfer r: 0.3 mm minimum, r1: 0.15 mm minimum. Grease charge: 0.29 g per bearing.

Interchange guidance

SKF 71906 ACD/P4ADGA is the same size at the same 25° contact angle and the same light preload class. FAG HCB71906-E-T-P4S shares the envelope and angle but runs ceramic balls, so it is a related size. Fafnir 3MM9306WICRDUL is the Timken cross for this envelope.