SNR7208CDUJ74Super-Precision Angular Contact Ball Bearing 40x80x18 mm 15 Degree ABEC 7 Duplex Universal Pair Light Preload

Product Description

What this part is

A super-precision angular contact ball bearing in the 7208 size, supplied as a factory-matched duplex pair. Bore 40 mm, outside diameter 80 mm, width 18 mm per bearing.

Decoding the designation

7208 — ISO angular contact 72-series: 40 mm bore, 80 mm outside diameter, 18 mm width.
C — 15° contact angle in the SNR scheme.
DU — duplex universal pair.
J74 — super-precision class at light preload in the SNR suffix scheme. The equivalent designation in the RHP scheme is 7208-C-T-DUL-P4, which places it at ABEC 7 with a light preload.

What these specs mean in practice

A 15° contact angle is the high-speed end of the angular contact range: less centrifugal ball loading and lower heat generation than a 25° bearing of the same envelope, and proportionally less thrust capacity. Light preload gives the lowest running friction and the lowest steady-state temperature rise of the preload grades, at correspondingly lower axial stiffness than a medium or heavy set. Universal grinding lets the pair develop that preload from the ground ring faces alone, without shims or ground spacers.

Quantity and configuration

2 Pcs — one matched duplex pair. The set can be arranged back-to-back, face-to-face or in tandem.

Fitting notes

The preload is ground into the ring faces and is realised only when both inner rings and both outer rings are clamped solidly against their seats. Alignment marks on the outer ring faces set the intended arrangement.

Interchange guidance

Genuine same-spec equivalent: RHP 7208-C-T-DUL-P4, a 15° light-preload universal pair at the same precision class. Same-envelope 7208 bearings at a 25° or 40° contact angle, or at medium or heavy preload such as the SNR J84 grade, are related sizes rather than interchanges.