NSK7213C1TDTP4Super Precision Angular Contact Ball Bearing Pair 65x120x23 mm, 15° Contact Angle, Tandem Matched DT, ABEC 7

Product Description

What this part is

A tandem-matched pair of super-precision angular contact ball bearings in the 65 mm bore × 120 mm outside diameter × 23 mm width envelope, the ISO 7213 size. Single row each, machined phenolic cage, ground as a set.

Decoding the designation

In the NSK super-precision scheme C is a 15° contact angle, distinct from A at 30° and A5 at 25°, so a 7213C and a 7213A5 are different bearings sharing one envelope. T is the machined phenolic cage, DT is duplex tandem, a factory-matched set, and P4 is the class equivalent to ABEC 7.

What tandem matching does

In a tandem arrangement both bearings face the same direction, so the two contact-angle lines run parallel and the thrust load divides between them. That gives roughly twice the one-direction thrust capacity of a single bearing. It is the arrangement chosen where thrust in a known single direction is heavy, and it is distinct from a back-to-back or face-to-face pair, which locate a shaft axially in both directions instead. A tandem set is not a substitute for a DB or DF pair in a housing designed around one of those.

Thrust direction

A tandem set carries radial load together with thrust in one direction only. Axial location in the opposite direction comes from a further bearing opposed to this set.

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 per row, which is part of why two rows are put in tandem when thrust is the governing load. 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.

Mounting data

Total width of the set clamped solid: 46 mm. Individual bearing width: 23 mm. Bore: 65 mm. Outside diameter: 120 mm.

Quantity and configuration

2 Pcs. One factory-matched tandem pair, 46 mm total width when clamped solid, supplied as bare bearings. The set is matched as a unit and the two rings are ground together.

Interchange guidance

The RHP counterpart designation is 7213CTDTP4 and the Fafnir-scheme equivalent is Timken 2MM213WI CR TUL, the 2MM prefix likewise denoting 15°. A 7213 in this envelope at 25° or 30°, or matched back-to-back or face-to-face rather than in tandem, is a related size rather than a substitution.