NDHQ20213DTT7AAngular Contact Ball Bearing Tandem Duplex Set 65x120x23 mm ABEC-7 Heavy Preload Phenolic Separator

Product Description

What this part is

New Departure Hyatt Q20213DTT7A single-row angular contact ball bearing, 65 mm bore, 120 mm outside diameter, 23 mm width. Open on both faces, phenolic ball separator, faces flush ground for duplex tandem mounting.

Decoding the designation

Q – nonmetallic (phenolic) ball separator
20213 – New Departure 20200 angular contact series; bore code 13 = 65 mm; ISO 7213 dimensional envelope
DT – duplex tandem set, all faces flush ground to preload requirement for universal mounting in tandem, back-to-back or face-to-face
T – heavy preload
7 – ABEC-7 tolerance class
A – rust-preventive slush

What these specs mean in practice

Heavy preload is the top of the three NDH duplex classes — L light, X medium, T heavy. It buys the highest axial and radial stiffness and the tightest axial position control, and it costs running torque, heat and limiting speed, which is why heavy-preload sets appear in boring and grinding spindles rather than high-rpm positions. A phenolic separator runs quieter and lighter than a machined bronze cage and holds oil in the fabric laminate, with a service temperature ceiling well below a metal cage. Two rows in tandem split one-direction thrust between them, roughly doubling the axial capacity of a single row.

Published specifications

Bore: 65 mm (2.5591 in)
Outside diameter: 120 mm (4.7244 in)
Width, each bearing: 23 mm (0.9055 in)
Rows: 1 per bearing
Rolling element: ball
Closure: open
Precision class: ABEC-7
Preload: heavy (T)
Separator: phenolic
Arrangement: duplex tandem, universally ground

Quantity and configuration

2 Pcs, one matched tandem set. A DT designation describes two single-row bearings ground to work together, not a double-row bearing.

Fitting notes

The ground faces of a universally ground set are assembled with the set markings aligned as supplied. Shaft and housing seats are held to the tolerance grade of the bearing, and clamping loads pass through the ring faces rather than the separator. Preload is set by the flush-ground faces once the rings are clamped solid.

Interchange guidance

The 65 x 120 x 23 mm envelope matches the ISO 7213 series. New Departure Hyatt was a General Motors division and the line later passed through Delphi, so this is an obsolete designation searched alongside the ISO number. A same-envelope bearing built to a different contact angle, preload class or separator material is a related size rather than an interchange.