RHP7008TDUMP4Angular Contact Ball Bearing — 40 mm ID, 68 mm OD, 15 mm Width, Straight Bore, Open, Medium Preload, Phenolic Outer-Ring-Guided Cage, P4 / ABEC 7

Product Description

What this part is

RHP 7008TDUMP4 super-precision angular contact ball bearings, supplied as a matched duplex pair. Bore: 40 mm (1.5748 in). Outside Diameter: 68 mm (2.6772 in). Overall Width: 15 mm (0.5906 in) per bearing. Total Width: 30 mm (1.1811 in) assembled. Closure Type: Open, both faces. Bore Type: Straight. Preload: Medium (M). Cage Type: Machined, outer ring guided. Cage Material: Laminated phenolic resin. Precision Class: P4 (ISO Class 4); RHP class code EP7; ABEC 7. Bearing Material: Carbon chrome bearing steel, BS970 534A99/535A99 or SAE 52100. Rolling Elements: Ball. Number Of Rows: 1 per bearing. Series: ISO series 10 (70xx). The carton also carries MM9108WI CR DUM.

Decoding the designation

7 — single-row angular contact ball bearing.

0 — ISO dimension series 10.

08 — bore code 08, a 40 mm bore.

T — laminated phenolic resin cage, outer ring guided; the CR on the Fafnir carton cross reads the same way.

DU — universally faced duplex set.

M — medium preload.

P4 — ISO Class 4, RHP class code EP7, ABEC 7. The alternate designation 7008TDUMEP7 gives the same class.

Dimensions and accuracy

Running Accuracy at P4: inner ring radial runout Kia 4 µm maximum at 40 mm bore; outer ring radial runout Kea 5 µm maximum at 68 mm outside diameter. Item weight: 0.189 kg (0.417 lb) per bearing.

What these specs mean in practice

Medium preload sits between the low-heat light setting and the maximum-stiffness heavy setting, so the pair holds shaft position firmly while running cooler than a heavy-preload set. The machined phenolic cage is light and self-lubricating, and outer ring guidance keeps it stable at speed. P4 accuracy controls bore, outside diameter and running runout to super-precision tolerances.

Quantity and configuration

Unit Quantity: 2 Pcs, a matched universal duplex set. Each bearing is single row and open.

Mounting data

Shaft abutment diameter d1: 46 mm minimum. Housing abutment diameter D1: 62 mm maximum. Outer ring abutment D2: 63 mm maximum. Chamfer r: 1.0 mm minimum. Chamfer r1: 0.6 mm minimum. Internal free volume: 8.2 cm3 per bearing. PCD of lubrication jets: 50.0 mm. The pair goes onto the shaft in the orientation marked on the rings, with the scribe lines aligned, and the faces seat against square ground shoulders.

Interchange guidance

The Fafnir carton cross MM9108WI CR DUM matches this bearing element for element: 9108 maps to ISO 7008, CR is the phenolic cage and DUM the medium-preload duplex. An interchange needs the same 40 x 68 x 15 mm envelope, the same medium preload, the same P4 or EP7 class and the same contact angle as the piece on the shelf. The DUL and DUH versions of this number differ in preload.