STO15 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 STO15 model number is decoded

envelope 15×35×11.8 mm: the 35 mm outside diameter is the track-running surface — a thick-walled outer ring over a 15 mm bore — and the 11.8 mm width sets the contact width on the mating track the catalogue lists C 9.1 kN and C0 11.1 kN for the STO yoke-type track roller with inner ring, without axial guidance; the C/C0 ratio of 0.82 reflects a rolling-element pack sized for heavy static track loading, and the 10.0 mm radial section gives the outer ring its bending stiffness fatigue load limit Cur is 1.67 kN at 15 mm bore, equivalent to 0.61 kN of dynamic rating per millimetre — the limiting speed is 3,300 r/min and, as for HR1 track rollers, no thermal reference speed is published the 15 mm bore takes the mounting pin or shaft; across the 11.8 mm contact width the dynamic rating works out to 0.77 kN per millimetre of rolling-element complement mass is 63 g, or 0.15 g per mm² of the 35×11.8 mm track envelope — inertia that the drive must accelerate on every index of the cam with a 15 mm pin bore the 11.8 mm width and 9.1 kN C rating suit high-cycle industrial machinery rather than instrument duty STO is the basic yoke-type track roller with inner ring and without axial guidance: it runs on a normal-tolerance pin through its 15 mm bore At 63 g the roller suits small indexing and transfer mechanisms; without flanges a bent pin or angled track produces edge loading at the outer-ring lips Typical applications include automatic assembly machine carriages, automotive welding jig rollers and linear rail and profile track guidance, where the 35 mm track diameter and 9.1 kN dynamic rating match the duty. In automatic assembly machine carriages the unit fits a compact 15 mm seat, and in automotive welding jig rollers the 63 g mass keeps follower kinetics light. Designers also specify it for linear rail and profile track guidance, relying on the 11.8 mm width and the published 11.1 kN static rating. Sealed PP/2RSR units are greased for life: never add a grease nipple, and respect the lower limiting speed imposed by the rubbing lips. The pin or shaft is part of the bearing system: harden it for RSTO/RNA22 positions, and size its deflection because the roller cannot compensate for a bent pin.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Sealed PP/2RSR units are greased for life: never add a grease nipple, and respect the lower limiting speed imposed by the rubbing lips.
• The pin or shaft is part of the bearing system: harden it for RSTO/RNA22 positions, and size its deflection because the roller cannot compensate for a bent pin.
• Yoke lugs must support the pin on both sides over its full length — single-sided support turns the pin into a cantilever beam.