RHP7006CTDUMP4Super Precision Angular Contact Ball Bearing Matched Pair – Straight Bore, 30 mm ID, 55 mm OD, 13 mm Width, Open, 15° Contact Angle, Medium Preload, ABEC 7, 2 Pcs.

Product Description

What this part is

RHP 7006CTDUMP4 super precision angular contact ball bearings, supplied as a factory-matched duplex pair. 30 mm bore, 55 mm outside diameter, 13 mm width per bearing. Open on both faces, phenolic cage, 15° contact angle, medium preload, ABEC 7 precision. The carton also carries the equivalent Fafnir-scheme designation 2MM9106WI CR DUM.

Decoding the designation

7006 gives an angular contact bearing in the 70 dimension series with bore code 06, a 30 mm bore. C is the RHP and NSK code for 15°, and the Fafnir 2MM prefix on the alternate marking reads 15° as well. T is the fabric-base laminate phenolic cage, matching the CR code on that same marking. DU marks a duplex matched set and M medium preload. P4 is ISO Class 4, equivalent to ABEC 7.

What these specs mean in practice

A duplex pair is ground at the factory so the two rings sit flush with a known preload built in, which removes the shimming work and gives a repeatable axial stiffness. Medium preload sits between the light setting used for maximum speed and the heavy setting used for maximum rigidity, and is the usual choice where a spindle needs both. The 15° contact angle biases the pair toward speed rather than thrust capacity. Phenolic cages are light and self-lubricating, which supports high shaft speeds and a 120°C ceiling.

Quantity and configuration

2 Pcs, one matched duplex pair. The arrangement mark is ground on the outer ring faces; the two rings are assembled with those marks aligned so the built-in preload is realised. The listed load ratings and limiting speed are per bearing.

Fitting notes

Assembly is dry and clean, with an interference fit on the inner rings and a location fit in the housing bore. The rings are clamped fully home against both the shaft shoulder and the housing shoulder so the ground offset closes and the preload comes up to its design value. Heating is applied to the shaft rather than the bearing because of the phenolic cage.

Interchange guidance

Another maker’s 30 x 55 x 13 mm 15° duplex pair at medium preload and ABEC 7 substitutes directly. A single universal bearing of the same number, an SU part, is a related size rather than an interchange: it is ground for field matching and carries no built-in duplex offset. Parts at light or heavy preload, or at a 25° angle, are likewise related sizes.