SNR7008CDUJ74Super-Precision Angular Contact Ball Bearing 40x68x15 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 7008 size, supplied as a factory-matched duplex pair. Bore 40 mm, outside diameter 68 mm, width 15 mm per bearing.

Decoding the designation

7008 — ISO angular contact 70-series: 40 mm bore, 68 mm outside diameter, 15 mm width. The 70 series is the light section for this bore.
C — 15° contact angle in the SNR scheme.
DU — duplex universal pair.
J74 — super-precision class at light preload. The equivalent designation in the RHP scheme is 7008-C-T-DUL-P4, which places it at ABEC 7 with a light preload.

What these specs mean in practice

The 15° contact angle and the light 70-series section together put this at the high-speed, low-heat end of the range for a 40 mm shaft, with proportionally less thrust capacity than a 25° or heavier-section bearing. Light preload gives the lowest friction and the lowest steady-state temperature rise of the preload grades, at correspondingly lower axial stiffness. The thin 70-series section also keeps rotating mass down, which is part of what makes the speed available.

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 7008-C-T-DUL-P4, a 15° light-preload universal pair at the same precision class and the same 40 x 68 x 15 mm section. Same-envelope 7008 bearings at a 25° contact angle, or at medium or heavy preload such as the SNR J84 grade, are related sizes rather than interchanges. A 7208 is a heavier section on the same 40 mm bore, not a substitute.