RHP7217CTSULP4Super Precision Angular Contact Ball Bearing 85x150x28 mm, 15° Contact Angle, Phenolic Cage, ABEC 7, Light Preload, Single Universally Ground, Medium 72-Series Section

Product Description

Part identity

RHP (now NSK) 7217CTSULP4 super precision angular contact ball bearing, single row. Brand: RHP. Designation: 7217CTSULP4. Base number: 7217C. Series: 72 (ISO dimension series 02, medium section). Bore code: 17. Contact angle: 15°. Precision class: P4 (ISO class 4, ABEC 7, RHP EP7). Preload: light (L). Grouping: SU, single universal. Closure: open. Number of rows: 1. Rolling elements: balls. Harmonization code: 8482.10.50. Unit quantity: 1 bearing.

Dimensions

Bore d: 85 mm. Outside diameter D: 150 mm. Width B: 28 mm. Ring chamfer r min: 2.5 mm. Second chamfer r1 min: 1.0 mm. Design units: metric. Mass: 1.782 kg (3.93 lb). Bearing material: through-hardened carbon chrome bearing steel to BS970 534A99 / 535A99, equivalent to SAE 52100.

Load ratings and speeds

Basic dynamic load rating Cr: 107 000 N (107.0 kN). Basic static load rating C0r: 90 500 N (90.5 kN). Limiting speed with oil/air lubrication: 14 300 rev/min. Limiting speed with grease lubrication: 8 500 rev/min. Both speed figures are for a single bearing under spring preload with the inner ring rotating; a back-to-back pair at light preload runs at 0.80 of them, a face-to-face pair is reduced by a further 50 per cent, and a spring-loaded tandem pair carries a factor of 0.95.

Preload and stiffness

Axial preload for a light-preload pair in the 72-series 15° range at bore code 17: 690 N. Axial stiffness for the same pair: 120 N/µm. For comparison within the same range, the extra-light grade is 345 N and 88 N/µm, medium is 1 670 N and 177 N/µm, and heavy is 3 330 N and 251 N/µm.

Mounting data

Effective load centre a: 29.7 mm. Abutment diameters: d1 min 95 mm, D1 max 140 mm, D2 max 144 mm. Internal free volume: 78.5 cm³. Pitch circle diameter for lubrication jets dT: 109.8 mm. Maximum recommended operating temperature for a laminated phenolic resin cage: 120 °C. Recommended shaft fit at P4 in this diameter range: +3 to −3 µm, a mean 3T interference. Recommended housing fit at P4 for a locating position: +7 to −3 µm, a mean 7C clearance.

Designation breakdown

7 is a single-row angular contact ball bearing. 2 is RHP dimension series 02, the ISO 72 medium section. 17 is the bore code for 85 mm. C is the 15° contact angle in the RHP scheme, matching C in NSK’s. T is the outer-ring guided laminated phenolic cage, written TR in full. SU is single universal grouping. L is light preload. P4 is precision grade 4. The Timken/Fafnir world number 2MM217WI CR SUL reads the same way in a different scheme: 2MM is a 15° contact angle, CR a phenolic outer-land-riding cage, SUL single universally ground at light preload. 217HDL is a legacy RHP-era designation for the same bearing.

Cage and contact angle

Cage type: machined one-piece, outer-ring guided. Cage material: laminated phenolic resin. The material and design suit high rotational speed and quiet running, and the cage’s own porosity retains lubricant. A 15° contact angle keeps the ball contact line closer to the radial plane, so less of the load turns into thrust and ball centrifugal, gyroscopic and cage loading stay low. The result is higher permissible speed and greater radial stiffness than the 25° variant of the same size, with lower axial capacity: the 25° 7217A5 runs to 12 500 rev/min on oil/air at Cr 102 000 N and C0r 86 500 N, against 14 300 rev/min and Cr 107 000 N here.

Universal face control and arrangement

The inner and outer rings are the same width and the relative positions of the faces on both sides of the bearing are adjusted at manufacture so that a predetermined preload force exists once the bearing is clamped against a partner of the same designation. A universally faced bearing therefore mounts back-to-back or face-to-face at the same preload value with no shims and no ground spacers, and shares load equally in tandem. Back-to-back (DB) mounting produces the highest radial and moment stiffness; face-to-face (DF) accommodates shaft-to-housing misalignment; tandem (DT) shares thrust in one direction between two bearings. The high point of radial runout is marked by a small circle or burnished spot on the inner ring face, and a V line on the outer ring outside diameter marks the direction of the contact angle.

Applications

Large machine tool spindles, grinding spindles, milling and turning centres, high-speed rotary and indexing tables, precision gearboxes, and test rigs.

Interchange

NSK designations for the same 15° P4 single universal light-preload bearing: 7217CTRSULP4 (phenolic cage) and 7217CTYNSULP4 (resin cage). Timken/Fafnir: 2MM217WI CR SUL, also written 2MM217WICRSUL and 2MM217WI-CR-SUL; MM-prefixed Fafnir numbers normally carry P4S tolerance. SKF 7217 CD/P4A and 7217 CDGA/P4A and FAG B7217-C-T-P4S-UL have the same 85x150x28 mm size and 15° angle; their preload follows each maker’s own suffix. Legacy and alternative forms carried on this record: 217HDL, B7217CTPAP4UL, 7217C-T-SUL-P4, 7217 C T SUL P4, 7217C, 7217. The 25° and 30° bearings share the 85x150x28 mm size with a different contact angle, load rating and speed capability.