NSK7010CTDBC8P4Super-Precision Angular Contact Ball Bearing – Straight Bore, 50 mm ID, 80 mm OD, 16 mm Width, Open, 15° Contact Angle, Medium Preload, Matched Back-to-Back Pair, 2 Pcs.

Product Description

What this part is

An NSK 7010CTDBC8P4 super-precision angular contact ball bearing, supplied as a factory-matched back-to-back pair. Bore 50 mm, outside diameter 80 mm, width 16 mm per bearing, giving 32 mm total width across the mounted pair. One row of balls per bearing, open on both faces, running in a phenolic laminate cage guided on the outer ring land.

Decoding the designation

7010 is the ISO 70 dimension series at a 50 mm bore. C is a 15° contact angle in NSK’s scheme. DB specifies a duplex pair arranged back-to-back. P4 is precision class ABEC 7. The carton also carries the Timken/Fafnir number 2MM9110WI-DBM: the 9100WI series maps to the ISO 70xx family so 9110 is a 7010, the 2MM prefix confirms 15°, CR confirms the outer-land-riding phenolic cage, and the DBM ending confirms a back-to-back pair at medium preload.

What these specs mean in practice

A 15° contact angle directs load closer to the radial plane, favouring speed and radial stiffness; a 25° bearing on the same envelope carries more thrust and runs slower. A back-to-back pair sets the two contact lines diverging outwards, which gives a wide effective bearing spread and high resistance to overturning moments — the standard arrangement for the front position of a machine tool spindle. Medium preload sits between the low-friction, high-speed light setting and the stiff, hotter-running heavy setting. The phenolic laminate cage is light, self-lubricating and quiet at speed.

Quantity and configuration

Two bearings, supplied as a matched back-to-back pair. Mounted this way the set takes thrust in both directions and carries moment loads. The ground ring faces establish medium preload when clamped solid. Because the set is preloaded rather than clearance-set, radial internal clearance does not apply.

Fitting notes

The pair mounts as a unit with the wide-faced outer rings together; preload is established by clamping the ground faces solid, so no shim stack or spacer is required. Shaft and housing seats held to ISO 4 or better preserve the running accuracy the P4 class buys. Grease fill for a preloaded phenolic-caged spindle bearing is typically 15 to 20 percent of free space.

Interchange guidance

Same-specification 15° back-to-back equivalents on this envelope include the Timken/Fafnir 2MM9110WI-DBM and the FAG B7010-C-T-P4S-DBM. The SKF 7010 CD/P4A and NSK 7010CTYNDBC8P4 share the 15° angle and the 50 x 80 x 16 mm envelope; the latter carries a polyamide cage rather than phenolic. A 7010 ACD or a 3MM9110WI on the same envelope is a 25° bearing, and a DF or DT version is a different arrangement — both are related sizes rather than substitutions.