RHP7205CTDULP4Super Precision Angular Contact Ball Bearing Matched Duplex Pair 25 x 52 x 15 mm 15 Degree Phenolic Cage Light Preload

Product Description

What this part is

A matched duplex pair of RHP 7205C single-row super-precision angular contact ball bearings. Bore: 25 mm. Outside Diameter: 52 mm. Width: 15 mm per bearing. Total Width: 30 mm for the pair. Contact Angle: 15°. Precision Class: P4 (ISO Class 4 / ABEC 7 / British Standard EP7). Cage Type: machined, outer-ring guided. Cage Material: laminated phenolic resin. Bearing Material: carbon chrome bearing steel, BS970 534A99/535A99 or SAE 52100. Closure: open, both faces. Series: ISO series 02 (72xx).

Decoding the designation

7205 — ISO dimension series 02, bore code 05, giving 25 x 52 x 15 mm.

C — 15° contact angle.

T — machined laminated phenolic resin cage, guided on the outer ring.

DU — matched duplex pair with universal face control.

L — light preload.

P4 — ISO Class 4, ABEC 7, RHP class code EP7.

The equivalent RHP B-series form is B7205X2TADULEP7, in which X2 reads the angle a second way as 15° and EP7 restates the class.

Load ratings and speed

Dynamic Load Rating Cr: 16,600 N (16.6 kN). Static Load Rating C0r: 10,200 N (10.2 kN). Limiting Speed: 44,900 rev/min oil/air; 27,800 rev/min grease. Axial Preload, light: 78 N. Axial Stiffness, light preload: 36 N per micrometre. Effective load centre a: 12.7 mm. Maximum recommended operating temperature: 120 °C. Lubricant: Grease or oil.

The tabulated limiting speeds apply to a single bearing under spring preload with the inner ring rotating. A back-to-back pair at light preload takes a factor of 0.80, and a face-to-face pair takes a further 50 percent reduction from that. A spring-loaded tandem pair takes 0.95.

What these specs mean in practice

A 15° contact angle gives the highest limiting speed and the lowest axial stiffness of the standard angular contact angles, which is why it is the usual choice for fast, radially loaded spindles.

Light preload keeps running torque and heat generation down and leaves the most speed headroom of the standard preload grades. The laminated phenolic resin cage rides the outer-ring land, is light and retains an oil film well, and sets the temperature ceiling at 120 °C ahead of the steel.

Duplex universal face control means the inner and outer rings are the same width with pre-adjusted face positions, so the pieces mount back-to-back or face-to-face at the same light preload with no measured spacers, and in tandem they share load equally. The rings are ground together so the pair reaches the specified light preload clamped solid. The bearing is preload-set at manufacture.

Running Accuracy at ISO Class 4: inner ring radial runout Kia 2.5 µm at 25 mm bore; outer ring radial runout Kea 5 µm at 52 mm outside diameter.

Quantity and configuration

Unit Quantity: 2 Pcs, supplied as one matched duplex set. Number of Rows: 1 per bearing.

Thrust direction

Each bearing on its own takes thrust in one direction. Back-to-back or face-to-face, the pair takes thrust in both directions; in tandem it takes a larger load in one direction.

Mounting data

Shaft abutment diameter d1 min: 31 mm. Housing abutment diameter D1 max: 46 mm. D2 max: 47 mm. Chamfer r min: 1.0 mm. Chamfer r1 min: 0.6 mm. Mass: 0.128 kg per bearing, 0.256 kg per pair. Internal free volume: 6.2 cm³. PCD of lubrication jets: 35.5 mm.

Interchange guidance

NSK 7205CTRDULP4 is the current designation for the same bearing. The RHP B-series form is B7205X2TADULEP7 and the Fafnir-scheme number for the same 15° size is 2MM205WI-CR-DUL. A 7205A5 at 25° shares the 25 x 52 x 15 mm envelope and is a related size rather than an interchange. Harmonization Code: 8482.10.50.28.