RHP7306ETDULP4Super Precision Angular Contact Ball Bearing Pair 30x72x19 mm, 25° Contact Angle, Light Preload, ABEC 7

Product Description

What this part is

A matched pair of super-precision angular contact ball bearings in the 30 mm bore × 72 mm outside diameter × 19 mm width envelope, the ISO 7306 size. Single row each, machined cage, universally ground for matching in any of the three duplex arrangements.

Decoding the designation

This part carries two designations, and they cross-confirm each other. In 7306ETDULP4 the E is a 25° contact angle, T the machined phenolic cage, DUL duplex universal with light preload, and P4 the class equivalent to ABEC 7. In the B-series form 7306X3TADULEP7 the X3 independently gives the 25° angle and EP7 independently gives the P4 class. Both strings describe the same bearing.

What these specs mean in practice

A 25° contact angle carries more thrust and less speed than a 15° bearing of the same size, and correspondingly less radial load. It is the middle choice in the super-precision range, taken where a spindle sees substantial axial cutting load. Light preload favours speed and low heat generation over maximum axial rigidity. The phenolic cage is rated to 120 °C, which sets the practical temperature ceiling. The 19 mm width on a 30 mm bore puts this in the heavier 73 dimension series, giving more capacity than a 72- or 70-series bearing of the same bore.

Thrust direction

Each bearing carries radial load together with thrust in one direction only. Mounted back-to-back or face-to-face, the pair locates a shaft axially in both directions; mounted in tandem, both act in the same direction at roughly doubled thrust capacity.

Quantity and configuration

2 Pcs. One universally ground pair, supplied without spacers, locknut or housing.

Fitting notes

Universal grinding means the two rings stack back-to-back, face-to-face or in tandem and arrive at the specified light preload without shimming or hand grinding. Mounting is against a square clean shoulder, and the preload class is only realised when both outer rings seat fully in the housing bore.

Interchange guidance

RHP super-precision designations cross-reference directly to NSK, which acquired RHP and continued the numbering. The same-spec equivalents are NSK 7306A5TDULP4, where A5 is the NSK code for 25°, and Timken 3MM306WI CR DUL. A 7306 in the same envelope with a 15° or 40° angle, such as the 7306C or the plain 7306, is a related size rather than a substitution.