NSK7022CTYDULP4Super Precision Angular Contact Ball Bearing 110x170x28 mm, 15° Contact Angle, P4 Class, Phenolic Cage, Universally Ground, Light Preload

Product Description

What this part is

An NSK super-precision angular contact ball bearing in the 7022 envelope — 110 mm bore, 170 mm outside diameter, 28 mm width. Open type, 15° contact angle, phenolic cage, universally ground so it can be stacked with matching bearings at a defined light preload.

Decoding the designation

7022 — ISO 70 dimension series, bore code 22, giving a 110 mm bore. The envelope 110 x 170 x 28 mm agrees with the recorded dimensions.
C — in NSK’s scheme, a 15° contact angle. (NSK reads A as 30° and A5 as 25°, so the letter matters.)
TY — NSK’s phenolic (synthetic resin) cage designation.
SU — single, universally ground.
L — light preload.
P4 — ISO precision class 4, equivalent to ABEC 7.

Correcting the source data

The original listing gave the part number twice, in two forms that contradict each other: 7022CTYSULP4 (containing SU, single universally ground) and 7022-C-TY-DUL-P4 (containing DU, duplex universally ground). SU and DU are mutually exclusive. A bearing is either ground as a single or supplied as a matched duplex set; it cannot be both.

We have published the SU reading, because it matches the primary part number on the record and is the more conservative interpretation — a buyer told they are getting a single and receiving a single has no complaint, whereas a buyer expecting a matched pair and receiving one bearing has a dispute. The DUL form is retained as a cross-reference search term only, not as a specification.

If you need a matched duplex pair rather than a single universally ground bearing, contact us first and we will read the ring etching and the carton before you order.

What these specs mean in practice

15° is the high-speed end of the spindle range. The shallower angle keeps the load path closer to the radial plane, which cuts ball centrifugal and gyroscopic effects and lets the bearing run faster and cooler than a 25° or 30° bearing in the same envelope. The trade is axial stiffness and thrust capacity, so 15° suits grinding and high-speed milling and is usually the wrong choice for a heavy boring spindle taking interrupted cuts.

The phenolic cage is a real selling point and is often omitted from listings. Phenolic is self-lubricating, absorbs oil, and is far gentler on the balls than pressed steel during momentary oil starvation — which is why it is standard on high-speed spindle bearings. It also sets the temperature ceiling: phenolic cages are not for high-temperature service.

Universal grinding means the ring faces are ground so that any two bearings of the same designation will produce the correct preload when clamped together, in any of the three arrangements. Light preload gives the least stiffness, the least heat and the highest speed capability of the preload grades.

Published ratings and mounting data

Basic dynamic and static load ratings and limiting speed are deliberately blank. We could not retrieve NSK’s own published figures for the 7022C, and we have specifically declined to substitute the widely circulated figures for the 7022A5, which is a 25° bearing in the same envelope and therefore has different ratings. Distributor mirrors of NSK data are also known to be unreliable — we have previously found mirrored figures materially below NSK’s own for other designations. Contact NSK or an authorised distributor with the full designation if a certified rating is required.

Quantity and configuration

One bearing, understood as a single universally ground bearing rather than half of a matched set — subject to the confirmation note above.

Fitting notes

Observe the thrust-direction marking on the outer ring; an angular contact bearing fitted backwards loads the unsupported shoulder and fails quickly. Universally ground faces must never be shimmed, lapped or reground — the preload is built into them. Press only on the ring being fitted, never through the balls, and confirm shaft and housing are ground to a tolerance consistent with P4, or the accuracy is wasted.

Interchange guidance

ISO base number 7022. Contact-angle letters differ by maker: NSK C = 15°, A5 = 25°, A = 30°; Timken C = 15°, E = 25°; SKF AC = 25°. Always establish the scheme before treating a number as equivalent. We hold two other 7022-envelope bearings in different brands and classes — a Fafnir 3MM9122 at 25° and a FAG B7022E — so ask if you need a particular angle, class or preload.