NSK7206A5TRDULP4YSuper Precision Angular Contact Ball Bearing 30x62x16mm 30 Degree Contact Angle ABEC 7 Machined Phenolic Cage Single Universally Ground Light Preload Open

Product Description

What this part is

One NSK 7206A5TRSULP4Y super-precision angular contact ball bearing, 30 mm bore × 62 mm outside diameter × 16 mm width. Single row, 30° contact angle, machined phenolic cage, open, ABEC 7 precision, universally ground and set for light preload.

Decoding the designation

7206 – ISO base number, 30x62x16 mm boundary dimensions.A5 – 30° nominal contact angle in NSK’s angular contact scheme (NSK C would be 15°).TR – machined phenolic (textile-laminate) cage. NSK’s TY/TYN suffixes denote a polyamide cage instead, so TR is a meaningful difference, not a cosmetic one.SUL – Single, Universally ground, Light preload.P4 – ABEC 7 precision class (P4S would be ABEC 7/9, P5 would be ABEC 5).Y – an NSK special-specification suffix. NSK does not publish a public decode for it against this designation, and we will not guess at one from general industry convention.

Correcting the source data

Our legacy listing data carried the cross-reference string 7206-A5-TR-DUL-P4Y, which contradicts the actual part marking. SU and DU are mutually exclusive: SU designates a single universally ground bearing, DU designates a duplex universally ground pairing. The bearing in hand is marked SUL — a single. We have kept the DUL string in the cross-reference attributes because buyers search it, but the item supplied is a single universally ground bearing, not a duplex set.

Why 30° changes the job the bearing can do:
At 30°, this is the high-thrust end of the angular contact range. The steeper contact angle routes far more of the ball load into the axial direction, giving substantially higher thrust capacity and axial stiffness than a 15° bearing in the same 30x62x16 mm envelope. What you give up is speed and radial stiffness: the steeper load path increases centrifugal and gyroscopic loading on the balls and cage, which raises heat generation and lowers the practical speed ceiling. This makes 30° the right choice for ballscrew support, drilling and boring positions and heavily thrust-loaded spindle ends — and the wrong choice for a very high-speed grinding spindle that was designed around a 15° bearing.

Why universally ground matters

The U in SUL is the useful part. Universally ground rings are relieved to a controlled, symmetrical amount, so two bearings of this designation can be clamped together in any orientation — back-to-back, face-to-face or tandem — and will develop the specified light preload without a calculated spacer or shim stack. A non-universal single cannot be paired this way. If you want a duplex arrangement, buy two units of this same designation; pair light preload with light preload, never light against medium, or the resulting preload is neither specification.

Why a phenolic cage and not polyamide

The TR machined phenolic cage is light, dimensionally stable under centrifugal load and mildly oil-absorbent, which gives it real tolerance of marginal lubrication — the reason it remains the traditional choice for oil-mist and oil-air lubricated spindles. Practical temperature ceiling is in the region of 120 °C, and it should not be cleaned with aggressive solvents. Polyamide (TY/TYN) cages are cheaper and quieter but less tolerant of high temperature and certain lubricant chemistries.

Published ratings and mounting data

NSK does not publish dynamic (Cr) or static (C0r) load ratings, limiting speed, or preload force figures for the legacy 7206A5TRSULP4Y designation in any currently reachable source. That data for this generation of NSK super-precision product survives only in out-of-print paper catalogues. We have deliberately left those fields empty rather than borrowing figures from a modern sibling or another manufacturer — on a preloaded ABEC 7 spindle bearing, a plausible-looking wrong number is worse than an acknowledged gap. Request values from NSK engineering against this exact suffix.

Quantity and configuration

Quantity supplied is one (1) bearing, consistent with the SUL single designation.

Fitting notes

Treat this as a super-precision component. Confirm shaft and housing form and size to the tolerance class your spindle drawing specifies, because an ABEC 7 bearing cannot correct a loose or out-of-round housing. Mount with even axial pressure applied to the ring being fitted, never through the ball complement. Note ring face orientation before removing the old bearing, and keep the work area to a contamination standard that would look excessive for a commercial bearing.

Interchange guidance

Same-envelope 30x62x16 mm candidates at 30° include SKF 7206 ACD (25°, angle differs) and 7206 ACDGA, FAG B7206–E–T–P4S, NTN 7206A/7206ADB and NSK 7206A5TYNSULP4 (polyamide cage variant). The 15° NSK 7206CTRSULP4 shares the envelope but not the duty. Confirm contact angle, precision class, cage material, preload class and universal-grind status before substituting.