RHP7008CTDUMP4Super-Precision Angular Contact Ball Bearing Pair – Straight Bore, 40 mm ID, 68 mm OD, 15 mm Width Each, Open, 15° Contact Angle, Medium Preload, Universal Duplex, ABEC 7

Product Description

What this part is

RHP 7008CTDUMP4 super-precision angular contact ball bearings supplied as a universally ground duplex pair. Bore 40 mm, outside diameter 68 mm, width 15 mm per bearing, 30 mm across the assembled set. Straight bore, open on both faces, single row of balls per bearing, machined phenolic cage riding on the outer ring land.

Decoding the designation

70 is the ISO light angular contact dimension series and 08 is the bore code, giving a 40 mm bore. C denotes a 15° contact angle in the RHP scheme. T is a fabric-base laminate phenolic cage. DU marks universally ground duplex bearings and M sets medium preload. P4 is ISO Class 4, equivalent to ABEC 7. The carton also carries B7008X2TADUMEP7 and 2MM9108WICRDUM, whose X2 and 2MM codes confirm the 15° angle, whose CR code confirms the outer-land phenolic cage, and whose EP7 confirms the ABEC 7 class.

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness over thrust capacity, which suits a high-rpm grinding or milling spindle. Medium preload sits a step above light: it raises axial and radial stiffness and tightens running accuracy under load, at the cost of more heat generation and a lower speed ceiling. A phenolic cage guided on the outer ring land is light and self-lubricating, which offsets part of that speed penalty.

Quantity and configuration

Two pieces, a universally ground duplex pair. Universal grinding lets the two units stack as a back-to-back, face-to-face or tandem set with the medium preload built into the ground ring faces, so the pair takes thrust in both directions when mounted back-to-back or face-to-face.

Fitting notes

Ring faces are ground flat and square for direct abutment, so preload develops when the shaft nut and housing cap are drawn fully home. Phenolic cages suit oil mist and circulating oil lubrication.

Interchange guidance

Same 15° medium-preload equivalents are the SKF 7008 CD/P4ADGB, the FAG B7008-C-T-P4S-DUM and the NSK 7008CTYNDUMP4. The Fafnir 2MM9108WICRDUM is the same specification under the WI numbering scheme.