NSK7010CTYDBDC7P4Super-Precision Angular Contact Ball Bearing – Matched Triplex Set, Straight Bore, 50 mm ID, 80 mm OD, 16 mm Width Each, Open, 15° Contact Angle, Light Preload, DBD Two Back-to-Back Plus One Tandem, 3 Pcs.

Product Description

What this part is

An NSK 7010CTYDBDC7P4 super-precision angular contact ball bearing, supplied as a factory-matched three-bearing triplex set. Bore 50 mm, outside diameter 80 mm, width 16 mm per bearing, giving 48 mm total width across the mounted stack. 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, and C is a 15° contact angle in NSK’s scheme. DBD specifies a three-bearing arrangement: a back-to-back duplex pair with a third bearing added in tandem. P4 is precision class ABEC 7. The carton also carries the Timken/Fafnir number 2MM9110WI CR TUL, which confirms the reading from a second scheme: the 9100WI series maps to the ISO 70xx family so 9110 is a 7010, 2MM is 15°, CR is the outer-land-riding phenolic cage, and TUL is triplex, universally ground, light preload.

What these specs mean in practice

A triplex DBD stack puts two bearings opposing each other and a third alongside one of them. The result is high stiffness with an asymmetric thrust capacity: the tandem pair shares axial load in the direction it faces, roughly doubling capacity that way, while the single opposing bearing carries thrust the other way. That suits a spindle with a dominant cutting-thrust direction. A 15° contact angle keeps the load line closer to the radial plane, favouring speed and radial stiffness over pure thrust capacity. Light preload holds running accuracy and prevents ball skidding while keeping friction and heat low.

Quantity and configuration

Three bearings, supplied as a matched triplex set. The ground ring faces establish light preload across the whole stack when clamped solid, which is why the three are matched to each other as a unit. Because the set is preloaded rather than clearance-set, radial internal clearance does not apply.

Fitting notes

The stack mounts as a unit and the orientation of the tandem pair sets which direction carries the doubled thrust. 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

A substitution here has to match on four counts: the 50 x 80 x 16 mm envelope, the 15° contact angle, light preload, and the three-bearing DBD arrangement. The Timken/Fafnir 2MM9110WI-TUL is the direct equivalent. Single bearings and two-bearing duplex sets on this envelope — the SKF 7010 CD/P4A, the NSK 7010CTDBC8P4 — share the size and angle but not the configuration, which makes them related sizes rather than substitutions. A 7010 ACD or 3MM9110WI is a 25° bearing.