NDHQ20214DTX5Angular Contact Ball Bearing 70x125x24 mm, 7214 Envelope, Duplex Tandem (DT) Flush Ground, Open

Product Description

What this part is

An NDH Q20214DTX5 single-row angular contact ball bearing in the 7214 envelope — 70 mm bore, 125 mm outside diameter, 24 mm width. The ring faces are ground for duplex tandem mounting, so two of these bearings sit side by side facing the same direction and share one heavy thrust load. New Departure Hyatt was the bearing division of General Motors, and the Q prefix is its precision angular contact scheme.

Decoding the designation

Q20214 – NDH single-row angular contact ball bearing, 7214 envelope: 70 mm bore, 125 mm OD, 24 mm width
DT – duplex tandem: faces flush ground so a pair mounts in tandem, both rows facing the same direction
X5 – NDH internal preload and tolerance code, carried as a carton marking
A – NDH variant letter

What these specs mean in practice

Tandem duplexing is used when thrust runs in one direction and is too large for a single bearing. Both bearings carry the thrust together, roughly doubling the axial capacity of a single row, and the flush ground faces are what make the load share even. That grinding is the whole value of the DT designation: two ordinary angular contact bearings clamped together will not share load equally and one will fail early. A tandem pair does not locate the shaft against reverse thrust, so a third bearing or a shoulder handles the opposite direction.

Published specifications

Bore: 70 mm (2.7559 in)
Outside diameter: 125 mm (4.9213 in)
Width: 24 mm (0.9449 in)
Rows: 1
Rolling elements: balls
Arrangement: duplex tandem (DT), flush ground faces
Closure: open both faces
Material: through-hardened bearing steel

Quantity and configuration

Sold as 1 Pc, a single bearing ground for tandem mounting. The mating bearing of the tandem pair is not included, and no spacers, lock nut or shims are included.

Fitting notes

The bearing is directional: the wide outer ring land takes the thrust and faces away from the load. In a tandem set the two bearings go in with both wide lands facing the same way, and the inner rings are clamped together axially so the ground faces contact. Mounting is by press or induction heat onto a clean shaft seat, with force applied only to the ring being fitted. The open faces take lubricant from the surrounding arrangement.

Interchange guidance

A substitution must match both the 70 x 125 x 24 mm envelope and the tandem duplex grinding — for example a 7214 angular contact bearing supplied in a DT flush-ground pairing from Fafnir, SKF, FAG or NSK, in the same contact angle as the bearing it joins. A standard single 7214 in the same envelope is not flush ground for pairing, so it is a related size rather than an equivalent, and a 7214 in a different contact angle will not share load correctly with this one.