RHP7210ETSULP4Super Precision Angular Contact Ball Bearing 50x90x20 mm, 25° Contact Angle, Light Preload, ABEC 7

Product Description

What this part is

A single super-precision angular contact ball bearing in the 50 mm bore × 90 mm outside diameter × 20 mm width envelope, the ISO 7210 size. Single row, machined cage, universally ground.

Decoding the designation

This part carries three designations and they agree with one another. In 7210ETSULP4 the E is a 25° contact angle, T the machined phenolic cage, SUL a single universally ground bearing at light preload, and P4 the class equivalent to ABEC 7. In the B-series form B7210X3TAULEP7 the X3 independently gives the 25° angle and EP7 independently gives the P4 class. The Fafnir-scheme equivalent 3MM210WI CR SUL agrees again: its 3MM prefix denotes 25° and its CR element a phenolic cage riding on the outer ring land.

What these specs mean in practice

A 25° contact angle is the thrust-biased middle choice in the super-precision range. Axial capacity and axial stiffness both rise with the angle, so a 25° bearing holds a spindle’s axial position harder under cutting thrust than the 15° version of the same size, at the cost of limiting speed and added heat at equal duty. Light preload adds the least of that heat, suiting fast, moderately loaded spindles and grinding heads. The phenolic cage is light and holds an oil film well, and it sets the temperature ceiling at roughly 120 °C, which governs ahead of the steel.

Thrust direction

A single-row angular contact bearing carries radial load together with thrust in one direction only. Axial location in both directions comes from mounting a second bearing opposed to this one.

Universal grinding

The rings are universally ground, so two bearings of this designation and preload class pair in any of the three arrangements – back-to-back, face-to-face or tandem – and reach the specified light preload as ground.

Quantity and configuration

1 Pc. One single universally ground bearing at light preload, supplied as a bare bearing.

Interchange guidance

RHP super-precision designations cross-reference directly to NSK, which acquired RHP and continued the numbering. The same-spec equivalents are NSK 7210A5TSULP4, where A5 is the NSK code for 25°, and Timken 3MM210WI CR SUL. A 7210C at 15°, a plain 7210 at 40°, a medium or heavy preload version, or a P5 or P6 class version shares this envelope but is a related size rather than a substitution.