RHP7006ETDULP4Angular Contact Ball Bearing — 30 mm ID, 55 mm OD, 13 mm Width, Open, 25° Contact Angle, Light Preload, Phenolic Outer-Ring-Guided Cage, ABEC 7

Product Description

What this part is

RHP 7006E single-row super-precision angular contact ball bearings, supplied as a matched duplex pair. Bore: 30 mm. Outside Diameter: 55 mm. Overall Width: 13 mm per bearing. Total Width: 26 mm for the pair. Contact Angle: 25°. 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 Type: open, both faces. Series: RHP 70, ISO dimension series 10.

Decoding the designation

70 — ISO dimension series 10.

06 — bore code 06, a 30 mm bore.

E — 25° contact angle, the legacy RHP form of the current A5 suffix.

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

DU — matched duplex pair, universally face-controlled.

L — light preload.

P4 — ISO Class 4.

Load ratings and speed

Dynamic Load Rating Cr: 14,400 N (14.4 kN). Static Load Rating C0r: 9,800 N (9.8 kN). Limiting Speed, single bearing under spring preload: 37,000 rev/min oil/air; 22,900 rev/min grease. Limiting Speed, back-to-back light-preload pair: 29,600 rev/min oil/air; 18,320 rev/min grease. Axial preload, light: 120 N. Axial stiffness, light preload: 89 N per micrometre. Effective load centre a: 16.4 mm. Maximum recommended operating temperature: 120 °C, set by the laminated phenolic cage.

What these specs mean in practice

A 25° contact angle is the thrust-biased choice in this envelope. Axial capacity and axial stiffness both rise with contact angle, so a 25° pair holds a spindle’s axial position harder under cutting thrust than the 15° version of the same size, at a lower speed ceiling.

The laminated phenolic resin cage guided on the outer ring land is the high-speed arrangement. Phenolic is light, so cage inertia and ball-pocket loads stay low, and it retains an oil film well; land guidance keeps the cage running true at speed.

Light preload removes internal play, fixes the contact angle and makes axial position and runout repeatable, while adding the least friction and heat of the standard preload grades. That suits fast, moderately loaded spindles and grinding heads. Duplex universal face control converts the ground tolerances into the preload itself: 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, and in tandem they share load equally.

Running Accuracy at ISO Class 4: inner ring radial runout Kia 2.5 micrometres at 30 mm bore; outer ring radial runout Kea 5 micrometres at 55 mm outside diameter.

Quantity and configuration

Unit Quantity: 2 Pcs, supplied as one matched duplex pair, duplex ground as a set.

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: 36 mm. Housing abutment diameter D1 max: 49 mm. D2 max: 50 mm. Chamfer r min: 1.0 mm. Chamfer r1 min: 0.6 mm. Item weight: 0.114 kg per bearing, 0.228 kg per pair. Internal free volume: 5.3 cm3. PCD of lubrication jets: 39.5 mm.

Interchange guidance

NSK 7006A5TRDULP4 is the current designation for the same bearing. The Fafnir-scheme number for the same 25° 70-series size is 3MM9106WI-CR-DUL. Same-envelope bearings differing in contact angle, preload grade or tolerance class are related sizes rather than interchanges.