RHP7204CTDULP4Super Precision Angular Contact Ball Bearing Matched Pair 20x47x14 mm 15° ABEC 7 Light Preload

Product Description

What this part is

A duplex-ground matched pair of single-row super-precision angular contact ball bearings. Each bearing is 20 mm bore, 47 mm outside diameter, 14 mm width, ground to a 15° contact angle and a light preload band. The pair clamps as one unit at 28 mm total width.

Decoding the designation

The 72 prefix and bore code 04 give ISO dimension series 72 at a 20 mm bore. In the RHP scheme C is a 15° contact angle, T a machined phenolic laminate cage, DU duplex universal grinding, L the light preload grade, and P4 super-precision tolerances to ABEC 7 / ISO class 4. The alternate carton number B7204X2TADULEP7 confirms both readings independently: in the RHP B-series X2 is 15° and EP7 is the ABEC 7 class code.

What these specs mean in practice

A 15° contact angle is the speed-biased choice in this family. The shallow load line keeps ball centrifugal and gyroscopic effects low, so a 15° pair reaches a higher limiting speed and runs cooler than a 25° pair of the same envelope, giving up axial capacity and axial stiffness in exchange. On a small-bore spindle running fast under mostly radial load, that is the right trade.

Light preload trades stiffness for heat. Preload removes internal play, fixes the contact angle and makes axial position and runout repeatable, and the friction it creates goes into the rings as heat that shifts the preload as the spindle warms. The L grade adds the least of it, which is why light-preload duplex sets go into fast, moderately loaded spindles and grinding heads while M and H grades go into stiffer, slower stacks.

P4 holds bore, outside diameter, width and running accuracy to single-digit micron limits. Duplex grinding converts those tolerances into the preload itself: the ring faces are relieved by a measured amount, so clamping the pair solid produces the light preload directly with no shimming.

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

B7204X2TADULEP7 is the RHP B-series form of this envelope and angle, and 2MM204WI is the Fafnir-scheme number for the same 15° 72-series size. Same-envelope bearings differing in contact angle, preload grade or tolerance class — 7204E at 25°, the medium and heavy preload sets, and P0 or P5 class variants — are related sizes rather than interchanges. A single universally ground bearing of this size is a different item, since SU pieces are not ground to this pair’s stack height.