SNFAVB17-9CE0DULSuper-Precision Angular Contact Ball Bearing Matched Pair – Straight Bore, 17 mm ID, 30 mm OD, 7 mm Width, Open, 15° Contact Angle, Light Preload, Phenolic Cage, ABEC 7

Product Description

What this part is

SNFA VB17-9CE0DUL is a duplex matched pair of super-precision angular contact ball bearings, 17 mm bore by 30 mm outside diameter by 7 mm width per bearing, 14 mm across the mounted pair. The ISO equivalent designation is 71903, the thin 719 dimension series. Both bearings are open, with a phenolic resin cage and a straight bore. SNFA is a French super-precision manufacturer, now part of the SKF group.

Decoding the designation

The carton carries the SNFA number alongside its ISO and Fafnir equivalents. The 7903-C-T-P4-DUL reading gives C for a 15° contact angle, T for a phenolic cage, P4 for ABEC 7 tolerances and DUL for a duplex universal set at light preload. The Fafnir 2MM prefix independently confirms 15°. In the SNFA number, VB is the high-speed spindle series and 17 is the bore in millimetres.

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness; a 25° bearing of the same size carries more thrust and turns more slowly. The phenolic cage is light and self-lubricating, well suited to the high shaft speeds a 17 mm super-precision spindle bearing runs at, and it sets the practical temperature ceiling at 120°C. Light preload gives the least friction and heat of the preload ladder while still removing internal play.

Quantity and configuration

Two pieces, supplied as one matched pair. The rings are universally ground, so the pair mounts back-to-back, face-to-face or in tandem and develops the specified light preload in any of those arrangements. The set is preloaded rather than clearance-set, so no internal clearance class applies.

Fitting notes

The bore is straight and both bearings are supplied without a snap ring, so axial location comes from the housing shoulder and clamping arrangement. Either oil or grease suits the phenolic cage, with oil preferred at the upper end of the speed range.

Interchange guidance

SKF 71903 CD/P4ADGA is the direct equivalent, matching on envelope, 15° angle, ABEC 7 class and light preload. Fafnir 2MM9303WI-CR-DUL is the same set in Timken numbering, and NSK 7903CTRDULP4 is the NSK equivalent with the same phenolic cage. A 71903 ACD, 7903 A5 or 3MM9303WI is a 25° bearing on this envelope, so it is a related size rather than a substitution. A 2MM9304WI is a 20 mm bore, 20 x 37 x 9 mm bearing, a different envelope entirely.