RHP7008TDUMP4Super Precision Angular Contact Ball Bearing Matched Duplex Pair 40 x 68 x 15 mm 40 Degree ABEC 7 Medium Preload

Product Description

What this part is

A matched duplex pair of super-precision angular contact ball bearings, each 40 mm bore × 68 mm outside diameter × 15 mm width, in the ISO 7008 envelope.

Decoding the designation

7008 — single-row angular contact ball bearing, 100 dimension series, bore code 08, giving a 40 mm bore.
No angle letter — 40° contact angle in the RHP scheme. A C in that position would be 15° and an E would be 25°.
T — phenolic cage.
DU — duplex, a factory-matched set of two.
M — medium preload.
P4 — ISO precision class 4, equivalent to ABEC 7. RHP writes the same class as EP7.

What these specs mean in practice

A 40° contact angle is the high-thrust end of the angular contact range: it carries far more axial load and gives much higher axial stiffness than a 15° or 25° bearing in the same envelope, and gives up speed capability and radial rigidity in exchange. That combination suits screw drives, worm inputs and vertical spindles where thrust dominates. Medium preload sits between the low-heat light setting and the maximum-stiffness heavy setting. Phenolic places the working temperature ceiling near 120 °C.

Published specifications

Bore: 40 mm (1.5748 in)
Outside diameter: 68 mm (2.6772 in)
Width per bearing: 15 mm (0.5906 in)
Stack width, pair: 30 mm (1.1811 in)
Contact angle: 40°
Precision class: ISO P4 / ABEC 7 / RHP EP7
Preload: medium (M)
Rows per bearing: 1
Cage material: phenolic
Rolling elements: steel balls
Closure: open, both faces
ISO base number: 7008

Quantity and configuration

Matched duplex pair, 2 Pcs. The two bearings are ground as a set, and the pair carries the medium preload as supplied.

Fitting notes

Mounting is an interference fit on the shaft and a close fit in the housing bore, both held to super-precision spindle limits. The pair goes onto the shaft in the orientation marked on the rings, with the scribe lines aligned; faces seat against square ground shoulders, and a runout error at the shoulder transfers directly into the raceway.

Interchange guidance

Same-spec 40° P4 duplex equivalents in other schemes are the SKF 7008 B/P4ADGB, FAG B7008-B-T-P4S-DUM and NSK 7008BTYDUMP4. The 7008C and 7008E at 15° and 25°, and the Fafnir 2MM9108WI at 15°, share the 40 × 68 × 15 mm envelope at a different contact angle, which makes them related sizes rather than interchanges. The DUL and DUH versions differ in preload.