RHP7211RCTDULP4Super Precision Angular Contact Ball Bearing Matched Pair 55x100x21 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 55 mm bore, 100 mm outside diameter, 21 mm width, and the two rings are ground together to a 15° contact angle and a light preload band. The pair clamps as one unit at 42 mm total width.

Decoding the designation

The 72 prefix and bore code 11 give ISO dimension series 72 at a 55 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 carton also carries the Fafnir-scheme number 2MM7211WO, whose 2MM prefix independently confirms the 15° angle.

What these specs mean in practice

A 15° contact angle is the speed-biased choice in this family. The shallower load line keeps ball centrifugal and gyroscopic effects low, so a 15° pair carries a higher limiting speed and runs cooler than a 25° pair of the same envelope, while giving up axial capacity and axial stiffness. Preload removes internal play, fixes the contact angle and makes axial position and runout repeatable; the light grade adds the least heat of the preload classes, which is why light-preload duplex sets go into fast, moderately loaded spindles and grinding heads. P4 holds bore, outside diameter, width and running accuracy to single-digit micron limits, and duplex grinding converts those tolerances into the preload directly when the pair is clamped solid.

Published specifications

Dynamic Load Rating: 53 kN (11,915 lbf). Static Load Rating: 44 kN (9,892 lbf). Limiting Speed: 10,000 rpm. Total width, pair clamped: 42 mm. Tolerance class: P4 (ABEC 7 / ISO class 4).

Quantity and configuration

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

Interchange guidance

2MM7211WO is the Fafnir-scheme designation for this envelope and angle. Same-envelope bearings differing in contact angle, preload grade or tolerance class — 7211E 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 the same size is also a different item, since SU pieces are not ground to this pair’s stack height.