RHP7003TDUMP4Super Precision Angular Contact Ball Bearing Matched Pair 17x35x10 mm 40° ABEC 7 Medium Preload

Product Description

What this part is

A duplex-ground matched pair of single-row super-precision angular contact ball bearings. Each bearing is 17 mm bore, 35 mm outside diameter, 10 mm width, ground to a 40° contact angle and a medium preload band. The pair clamps as one unit at 20 mm total width.

Decoding the designation

The 70 prefix and bore code 03 give ISO dimension series 70 at a 17 mm bore. The contact angle is carried by the absence of an angle letter: in the RHP scheme C is 15° and E is 25°, and a designation with no angle letter at all is 40°. T is a machined phenolic laminate cage, DU duplex universal grinding, M the medium preload grade, and P4 super-precision tolerances to ABEC 7 / ISO class 4. The alternate carton number 7003TDUMEP7 confirms the class independently, EP7 being the RHP code for ABEC 7, and it likewise carries no angle letter.

What these specs mean in practice

A 40° contact angle is the steepest of the standard angular contact angles and it makes this a thrust bearing first. Axial capacity and axial stiffness rise steeply with contact angle, so a 40° pair carries far more thrust than the 15° or 25° bearings of the same envelope and locates a shaft axially far more rigidly. What it gives up is speed and radial capacity: the steep load line drives up ball centrifugal and gyroscopic effects, lowering the limiting speed and raising heat generation at equal duty, and less of the ball load resolves into the radial direction.

That makes the angle the single most important number on this record. A 7003 at 40°, a 7003C at 15° and a 7003E at 25° share an identical 17 x 35 x 10 mm envelope and will all physically fit the same seats, while behaving as three different bearings under load. Fitting the wrong one gives a spindle either too little axial stiffness or too little speed headroom.

Medium preload sits between light and heavy. Preload removes internal play, fixes the contact angle and makes axial position and runout repeatable; the friction it adds becomes heat that shifts the preload as the assembly warms. The M grade buys more stiffness than L at the cost of more heat.

Quantity and configuration

Matched pair, 2 Pcs, duplex ground as one set.

Fitting notes

The pair is assembled in the orientation its face marks indicate, most often back-to-back for moment stiffness, and the inner rings are clamped solid against one another so the ground relief sets the preload. A duplex set behaves as a single bearing, and its preload band of a few microns belongs to that specific pair. Shaft and housing seats at this class are ground and measured, typically j4 to k4 on the shaft and H5 to J5 in the housing.

Interchange guidance

7003TDUMEP7 is the alternate RHP form of the same pair. Same-envelope bearings differing in contact angle, preload grade or tolerance class are related sizes rather than interchanges, and on this record that distinction is sharper than usual: 7003C at 15° and 7003E at 25° are the same 17 x 35 x 10 mm size at different angles, not substitutes. The light and heavy preload grades and the P0 and P5 class variants are likewise related sizes. A single universally ground bearing of this size is a different item, since SU pieces are not ground to this pair’s stack height.