SNR7211CVDUJ74Matched Duplex Angular Contact Ball Bearing Set 55 x 100 x 21 mm, 15° Contact Angle, Light Preload

Product Description

What this part is

A matched duplex set of two single-row angular contact ball bearings, each 55 mm bore, 100 mm outside diameter, 21 mm width, giving 42 mm total width across the pair. The two rings are ground together at the factory so their faces produce a defined light preload when clamped together.

Decoding the designation

7211 — single-row angular contact ball bearing, 72 dimension series, bore code 11 = 55 mmC — 15° contact angleDU — duplex, two bearings ground as a matched setJ74 — light preload in the NTN-SNR super-precision preload scheme

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness over thrust capacity. Light preload holds the balls in defined contact with minimal added friction and heat, which suits high rotational speed and moderate axial load.

A duplex set works as a unit: the two bearings share the axial load, take thrust in both directions when mounted back-to-back or face-to-face, and hold the preload that the matched grinding established. Mixing one half of a set with an unmatched bearing gives an undefined preload.

The J74 code belongs to the NTN-SNR super-precision preload family and is distinct from the J20/J30/J40/J50 radial internal clearance codes used on standard bearings.

Quantity and configuration

Sale unit: 2 Pcs — one matched duplex setSingle row each, two rows total in the assemblyTotal width across the pair: 42 mm

Fitting notes

The set mounts with the marked ring faces together in the orientation the factory grind was made for, clamped square against a rigid shoulder so the preload lands as designed. Clamping force goes through the rings, never through the balls, and the outer ring seats in a housing bore that supports it across its full width.

Interchange guidance

The ISO base number 7211 C describes a 55 x 100 x 21 mm 15° single-row angular contact bearing. As a light-preload matched duplex set the equivalents are SKF 7211 CD/P4ADGA, NSK 7211CDUL and NTN 7211CDBGDL. Same-envelope parts differing in preload class (J84 medium) or contact angle are related sizes rather than interchanges, since preload and angle set the stiffness and speed of the assembly.