RHPSuper Precision Angular Contact Ball Bearing – Straight Bore, 85 mm ID, 150 mm OD, 28 mm Width, Open, 25° Contact Angle, Matched Tandem Pair

Product Description

What this part is

RHP 7217ETDTP4 super precision angular contact ball bearing set. Bore: 85 mm. Outside diameter: 150 mm. Width: 28 mm per bearing. Series: 72, ISO dimension series 02. Two single-row angular contact ball bearings, straight bore, open, matched as a tandem pair.

Decoding the designation

Contact Angle: 25°. Cage: machined laminated phenolic, outer-ring guided. Arrangement: DT, matched tandem pair. Preload: Not specified. Precision Grade: P4, equivalent to EP7, ABEC 7 and ISO Class 4. The same bearing carries the designations 7217-X3-TA-DT-EP7 and B7217ETPAP4.

What these specs mean in practice

Dynamic radial load rating (Cr) per bearing: 102,000 N. Static radial load rating (C0r) per bearing: 86,500 N. A tandem arrangement puts both contact angles the same way round, so the two bearings share thrust in one direction and roughly double the axial capacity of a single bearing, while taking no thrust in the reverse direction. A 25° contact angle carries more thrust and gives greater axial stiffness than a 15° bearing in the same envelope, at a lower speed ceiling. Limiting speed for a single bearing: 12,500 rpm on oil/air, 8,100 rpm on grease. As a spring-loaded tandem pair the oil/air figure is 11,875 rpm. Maximum recommended operating temperature: 120 °C. Rings and balls are through-hardened carbon chrome bearing steel to SAE 52100.

Quantity and configuration

2 Pcs, one matched tandem pair, sold together. Universal face control means the inner and outer rings are the same width and the ring faces are adjusted at manufacture, so the pair shares load equally in tandem without custom spacers. A third bearing mounted back-to-back against the tandem pair gives a DTB arrangement, which takes thrust in both directions.

Fitting notes

Shaft abutment diameter (d1): 95 mm minimum. Housing abutment diameters: D1 140 mm maximum, D2 144 mm maximum. Maximum shaft fillet radius: 2.5 mm. Maximum housing fillet radius: 1.0 mm. Effective load centre (a): 109.8 mm. Internal volume for grease charging: 78.5 cm³ per bearing. Mass: 1.78 kg per bearing. The high point of radial runout is marked by a burnished spot on the inner ring face and by a V line on the outer ring outside diameter. On a matched set the V lines fix the mounting order, and as standard the V points in the direction of maximum axial capacity with the load applied to the inner ring.

Interchange guidance

Closest at the same contact angle and precision class: NSK 7217A5TRDTP4 (DT tandem pair). SKF 7217 ACD/P4A and FAG B7217-E-T-P4S are single-bearing numbers; a tandem pair adds the DT code. Related sizes on the 85 x 150 x 28 mm envelope at 15°, not 25° substitutes: Timken Fafnir 2MM217WI CR DT and RHP 7217CTRDTP4.