RHP7211CTDUHP4Super Precision Angular Contact Ball Bearing – Straight Bore, 55 mm ID, 100 mm OD, 21 mm Width, Open, 15° Contact Angle, Universally Matchable Pair, Heavy Preload

Product Description

What this part is

An RHP 7211CTDUHP4 super-precision single-row angular contact ball bearing, supplied as a matched pair. Bore 55 mm, outside diameter 100 mm, width 21 mm per bearing. Straight bore, open on both faces, 15° contact angle, phenolic cage. RHP is now part of NSK.

Decoding the designation

7211 is the ISO 72 dimension series at a 55 mm bore. C is the RHP and NSK code for a 15° contact angle, where E would indicate 25° and no angle letter at all would mean 40°. T marks the phenolic cage. DU denotes universally matchable rings, and the H that follows sets the preload at the heavy step. P4 is ABEC 7.

Cross-confirmed designations

The carton also carries B7211X2TADUHEP7 and the Timken Fafnir equivalent 2MM211WI-CR-DUH. In the RHP B-series scheme X2 means 15° and EP7 means ABEC 7; in the Fafnir scheme the 2MM prefix likewise means 15°. All three numbering systems agree on the angle and the precision class.

What these specs mean in practice

A 15° contact angle favours speed and radial rigidity over thrust capacity. Heavy preload raises spindle stiffness and running accuracy at the cost of higher operating temperature and a lower speed ceiling, which is why it suits heavy-cut milling and boring spindles rather than high-rpm grinding. The phenolic cage is light, self-lubricating and tolerant of momentary lubricant starvation, with a service range of -30 °C to 120 °C.

Load ratings

Basic dynamic radial load rating 49.0 kN and basic static radial load rating 38.0 kN, each per bearing. Limiting speed 16,000 rpm. Weight 1.35 lb.

Quantity and configuration

Two bearings, universally ground as a matched heavy-preload set. Because the preload is set at manufacture, radial internal clearance does not apply. Supplied without a snap ring.

Interchange guidance

The ISO base number is 7211C. Same-angle, same-preload equivalents include the SKF 7211 CD/P4ADGC and the FAG B7211-C-T-P4S-DUH. A 7211E, 7211A or 7211B in the same envelope carries a different contact angle, and a DUL or DUM version carries a lighter preload; both are related sizes rather than substitutions.