NDHQ0L12DTXAngular Contact Ball Bearing Matched Tandem Pair DT 60x95x18mm 15 Degree

Product Description

What this part is

A matched tandem pair of New Departure Hyatt Q-series precision angular contact ball bearings on the 7012 envelope: 60 mm bore, 95 mm OD, 18 mm wide each, 36 mm stacked. NDH built precision ball bearings for machine tool and aerospace work, and the Q prefix denotes its precision angular contact line. Parts like this belong in spindles, ball screw ends and vertical shafts where one direction of thrust dominates.

Decoding the designation

Q — NDH precision angular contact ball bearing line0L12 — NDH size and design code; bore code 12 corresponds to the 60 mm bore, 7012 envelopeDT — duplex tandem, a factory-matched pair intended to be mounted facing the same directionX — NDH variant suffix carried on the carton; kept as a search term rather than published as a spec, since NDH’s definition for it is not published
The 7012C reference on the carton gives the contact angle: C is 15°.

What these specs mean in practice

A tandem pair is not the same thing as a back-to-back pair, and the difference decides whether the machine works. Both bearings face the same way, so their thrust capacity adds — roughly double the axial load of a single bearing — but only in one direction. A tandem pair gives no axial location the other way, so the shaft needs a second bearing or a shoulder to hold it. Mounting these back-to-back instead would locate the shaft both ways but halve the one-way thrust capacity and destroy the intended load sharing. The 15° contact angle favours speed and radial capacity over maximum thrust per bearing, which is why tandem stacking is used to make up the axial capacity.

Published specifications

Bore: 60 mmOutside diameter: 95 mmWidth: 18 mm each bearingTotal width mounted as a tandem pair: 36 mmContact angle: 15°Arrangement: duplex tandem (DT)Series: 7000 light, 7012 envelopeRows: single row eachClosure: open

Quantity and configuration

Two bearings, supplied as the factory-matched tandem set. Mount both facing the same direction, with the thrust load bearing on the high shoulders. Do not split the pair and do not substitute a bearing from another set — the matched grind is what makes the two bearings share load evenly.

Fitting notes

Identify the high-shoulder side of each outer ring before pressing and mark the faces so the arrangement can be reproduced at the next rebuild. A tandem pair must be clamped as a unit: leaving one ring unclamped lets the load fall entirely on one bearing. Mount clean, press only on the ring being fitted, and never drive mounting force through the balls. Because this is an older NDH part, check the shaft and housing seats for wear before assuming the original fits still apply.

Interchange guidance

Same-specification alternatives are 7012-envelope 15° angular contact bearings supplied as a matched tandem pair, such as 7012C DT sets and the Fafnir 2MM9112WI equivalent envelope in a tandem arrangement. Related but NOT interchangeable: a DB or DF (back-to-back / face-to-face) pair of the same size, a 7012A5 or 7012A at 25° or 30°, and any single 7012C bearing on its own. Arrangement and contact angle both have to match the machine design.