IKONAST25ZZNeedle Roller Bearing 25x52x20 mm NAST 25 ZZ Roller Follower

Product Description

What this is
An IKO NAST25ZZ separable roller follower — a yoke-type track roller, which is the pinned-through cousin of the stud-type cam follower. Instead of a threaded stud it has a plain inner ring, so it mounts on a shaft or pin carried between two supports. Bore 25 mm, outside diameter 52 mm, overall width 20 mm, inner ring width 16 mm.

Separable is the operative word: the outer ring, the needle roller cage and the inner ring come apart from one another, which is what makes this series straightforward to fit and to service. The outer ring surface is cylindrical, for flat track. ZZ means shielded — side plates that form a labyrinth against the outer ring rather than a rubbing seal, so there is no added drag.

Original IKO carton, one piece per box, marked NAST 25 ZZ / IKO / JAPAN on the ring itself.

How the part number breaks down
NA — IKO’s needle roller bearing family with a cage.

ST — the separable roller follower configuration: outer ring, needle roller cage and inner ring that can be taken apart from one another.

25 — the bore in millimetres: 25 mm. The outside diameter and width follow from the series — 52 mm and 20 mm at this bore.

ZZ — shield type, both sides. The plain NAST25 has no shields; NAST25R and NAST25ZZR carry an R suffix for the version without the inner ring.

Also written NAST-25-ZZ, NAST 25 ZZ and NAST25-ZZ, and dimensionally equivalent to the STO25ZZ size in other makers’ yoke track roller ranges.

Published figures

Bore: 25 mm
Outside diameter: 52 mm
Overall width: 20 mm
Inner ring width: 16 mm
Basic dynamic load rating: 30,500 N
Basic static load rating: 28,400 N
Rows: 1
Cage: steel
Closure: ZZ, shielded both sides
Outer ring surface: cylindrical
Construction: separable — outer ring, cage and inner ring
Made in Japan