NSK7002CTRDULP4YSuper Precision Angular Contact Ball Bearing Pair 15x32x9 mm, 15° Contact Angle, Phenolic Cage, Light Preload, Class Tighter Than P4

Product Description

What this part is

A matched pair of super-precision angular contact ball bearings in the 15 mm bore × 32 mm outside diameter × 9 mm width envelope, the ISO 7002 size. Single row each, phenolic cage, universally ground so the pair reaches its specified preload when clamped solid.

Decoding the designation

In the NSK super-precision scheme C is a 15° contact angle, distinct from A at 30° and A5 at 25°. TR is the machined phenolic cage guided on the outer ring land. DUL is duplex universal with light preload. P4Y is an NSK special tolerance class held tighter than the standard P4, and it is the element that sets this bearing apart from an ordinary P4 pair of the same size.

What the tolerance class buys

P4 already holds bore, outside diameter, width and running accuracy to single-digit micron limits. P4Y is held tighter still, which narrows the spread of radial and axial runout across a production batch. On a spindle that matters twice over: the tighter the runout band, the more repeatable the tool position, and the more predictable the preload once the pair is clamped, because preload depends on how accurately the ground ring faces relate to the raceways.

What these specs mean in practice

A 15° contact angle carries more radial load and runs faster than a 25° or 30° bearing of the same size, and carries correspondingly less thrust. Light preload adds the least heat of the three grades, which suits the high speeds a small-bore spindle bearing of this size normally runs at. The phenolic cage is light, so cage inertia and ball-pocket loads stay low, and it holds an oil film well; it sets the temperature ceiling at roughly 120 °C, which governs ahead of the steel.

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 the shaft axially in both directions, one row acting in each; mounted in tandem both act in the same direction at roughly doubled capacity.

Quantity and configuration

2 Pcs. One universally ground pair, 18 mm total width when clamped solid, 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 with no shimming or hand grinding. The pair is assembled in the orientation its face marks indicate and the inner rings are clamped solid against one another so the ground relief sets the preload. At this class the shaft and housing seats are ground and measured, and cleanliness governs the result.

Interchange guidance

The RHP counterpart designation is 7002CTDULP4 and the Fafnir-scheme equivalent is Timken 2MM9102WI CR DUL, the 2MM prefix likewise denoting 15°. A standard P4 pair in this envelope is a related size rather than a strict substitution, since it is held to a wider runout band than P4Y. A 7002A5 at 25°, or a medium or heavy preload set, is likewise a related size.