NSK90BCN19TDBBP4D + KL10BCA10Super Precision Angular Contact Bearing Set with Spacers — 90 mm ID, 125 mm OD, 18 mm Width Each, Open, Back-to-Back DBB, P4

Product Description

What this part is

NSK 90BCN19TDBBP4D, a high-speed super-precision angular contact ball bearing from NSK’s spindle range, supplied as a matched set with its KL10BCA10 spacers. Bore: 90 mm. Outside diameter: 125 mm. Width: 18 mm per bearing. Precision: P4, ABEC 7. Country of origin as recorded: Japan.

Decoding the order code

90: bore, 90 mm. 19: the dimension section, which puts this bearing on the 90 x 125 x 18 mm envelope shared with the ISO 71918. T: outer-ring-guided phenolic resin cage, rated to 120 °C and cleared to a 2.8 million dmn value. DBB: a back-to-back multi-row combination. P4: ISO Class 4 accuracy, ABEC 7. KL10BCA10: the matched inner and outer spacer group supplied with the set.

What these specs mean in practice

This is a thin-section, high-speed spindle bearing: a 17.5 mm radial section on a 90 mm bore, which keeps ball size and centrifugal loading down at speed. The outer-ring-guided phenolic cage holds its running position at high dmn values, and is cleared to roughly twice the dmn limit of a ball-guided polyamide cage. A back-to-back combination sets the effective load centres wide apart, which is what gives the set its moment stiffness and its ability to carry thrust in both directions. Ground spacers fix the axial spacing, so the preload is set at the factory across the whole stack rather than at assembly.

Quantity and configuration

One matched set, supplied with its KL10BCA10 inner and outer spacers, ground to suit the bearings it ships with. The set is arranged back-to-back.

Fitting notes

Both faces of each bearing are open. A back-to-back stack is assembled with the wide faces of the outer rings toward each other, with the ground spacers between the pairs. Bore and outside diameter tolerances are to ISO Class 4, so shaft and housing fits should be specified to match rather than to a standard-class table. The spacers are ground as a matched group with these bearings, so keeping them together preserves the factory preload.

Interchange guidance

The envelope is shared with ISO 71918 and with the NSK 7918 designation, both 90 x 125 x 18 mm. Those are related sizes on envelope: a 71918 from any maker carries its own contact angle, cage and preload codes, and each of those changes the part. The searchable forms of this designation include 90BCN19TDBBP4D, 90BCN19 T DBB P4 D, 90BCN19TDBBP4D+KL10BCA10, KL10BCA10, 71918 and 7918.