NSK7916A5TRSULP4YSuper-Precision Thin-Section Angular Contact Ball Bearing – Straight Bore, 80 mm ID, 110 mm OD, 16 mm Width, Open, 25° Contact Angle, Light Preload, Phenolic Cage, P4Y

Product Description

What this part is

An NSK 7916A5TRSULP4Y super-precision angular contact ball bearing, 80 mm bore, 110 mm outside diameter, 16 mm width. It is a thin-section 719-series design, ground as a universally matchable single at light preload and supplied open on both faces.

Decoding the designation

7916 is NSK’s short form for 71916, the ISO 719 thin-section series at an 80 mm bore. A5 is NSK’s 25° contact angle. TR is an outer-ring-guided machined phenolic resin cage, rated to 120 °C. SUL is a universally matchable single at light preload. P4Y is an NSK special accuracy class held tighter than standard P4, which is itself ABEC 7.

What these specs mean in practice

The 719 series puts a large bore inside a shallow cross-section, which is what makes it the usual choice for a compact machine tool spindle nose or a rotary table. A 25° contact angle takes appreciably more thrust than the 15° C-suffix version of the same envelope, at some cost in speed. Basic dynamic load rating is 33.5 kN and basic static load rating 36.5 kN; on a large-bore thin-section bearing the static figure sitting above the dynamic one is the normal relationship. Universal matching means any number of identical bearings can be set back-to-back, face-to-face or in tandem and will deliver the ground-in light preload.

Speed and temperature

Catalogue limiting speed is 12,000 rpm. The phenolic cage sets the upper continuous temperature at 120 °C, with a lower limit of −40 °C.

Quantity and configuration

One bearing per sale unit. As a universally matchable single, a set of any size can be built from identical units.

Fitting notes

Shaft and housing seats want grinding to super-precision limits to preserve the P4Y running accuracy. The ground reference face is marked, and on a stacked set the marked faces are brought together to establish the preload. Mounting force passes through the ring being fitted, not through the balls. The bearing arrives with a preservative film rather than a service lubricant.

Interchange guidance

SKF 71916 ACDGA/P4A and Fafnir 3MM9316WI occupy the same 80 x 110 x 16 mm envelope at 25° with light preload, and each maker’s cage, preload and matching suffixes are read in that maker’s own scheme. 7916A5TRDULP4Y is the same bearing supplied as a two-piece matched pair — a related configuration rather than a substitute. 7916CTRSULP4Y is the 15° version of the same envelope.