STO17 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (HR1 2026-09-25) · extracted 2026-09-30

Parameters extracted from the official FAG Rolling Bearings catalogue (HR1 2026-09-25); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the STO17 model number is decoded

envelope 17×40×15.8 mm: the 40 mm outside diameter is the track-running surface — a thick-walled outer ring over a 17 mm bore — and the 15.8 mm width sets the contact width on the mating track the catalogue lists C 14.2 kN and C0 18.2 kN for the STO yoke-type track roller with inner ring, without axial guidance; the C/C0 ratio of 0.78 reflects a rolling-element pack sized for heavy static track loading, and the 11.5 mm radial section gives the outer ring its bending stiffness fatigue load limit Cur is 2.55 kN at 17 mm bore, equivalent to 0.84 kN of dynamic rating per millimetre — the limiting speed is 2,800 r/min and, as for HR1 track rollers, no thermal reference speed is published the 17 mm bore takes the mounting pin or shaft; across the 15.8 mm contact width the dynamic rating works out to 0.90 kN per millimetre of rolling-element complement mass is 107 g, or 0.17 g per mm² of the 40×15.8 mm track envelope — inertia that the drive must accelerate on every index of the cam at 17 mm pin bore this size balances the 40 mm outside diameter against machineability of the adjacent parts — the most frequently specified band in the HR1 range Because the inner ring is supplied, the mounting pin only needs standard bearing-seat tolerance and surface — hardening to raceway quality is unnecessary Reading STO: yoke roller with inner ring, no flanges; the 15.8 mm-wide unit is located laterally by housing shoulders or circlips rather than by integral ribs Typical applications include conveyor transfer and diverting stations, robotic arm linear axes and automotive welding jig rollers, where the 40 mm track diameter and 14.2 kN dynamic rating match the duty. In conveyor transfer and diverting stations the unit fits a compact 17 mm seat, and in robotic arm linear axes the 107 g mass keeps follower kinetics light. Designers also specify it for automotive welding jig rollers, relying on the 15.8 mm width and the published 18.2 kN static rating. Flangeless STO/RSTO/RNA22/NA22 rollers need external axial location; circlips or shoulders must control end float or the roller walks off the track. Full-complement NATV/NUTR/PWTR rollers make heat and flat-spot easily — slow continuous rotation is fine, stationary load on a turning track is not.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Flangeless STO/RSTO/RNA22/NA22 rollers need external axial location; circlips or shoulders must control end float or the roller walks off the track.
• Full-complement NATV/NUTR/PWTR rollers make heat and flat-spot easily — slow continuous rotation is fine, stationary load on a turning track is not.
• The crowned outer profile tolerates only small skew; a track that departs by more than the catalogue angle still causes edge loading.