STO12 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 STO12 model number is decoded

envelope 12×32×11.8 mm: the 32 mm outside diameter is the track-running surface — a thick-walled outer ring over a 12 mm bore — and the 11.8 mm width sets the contact width on the mating track the catalogue lists C 9 kN and C0 10.4 kN for the STO yoke-type track roller with inner ring, without axial guidance; the C/C0 ratio of 0.87 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 1.56 kN at 12 mm bore, equivalent to 0.75 kN of dynamic rating per millimetre — the limiting speed is 4,500 r/min and, as for HR1 track rollers, no thermal reference speed is published the 12 mm bore takes the mounting pin or shaft; across the 11.8 mm contact width the dynamic rating works out to 0.76 kN per millimetre of rolling-element complement mass is 57 g, or 0.15 g per mm² of the 32×11.8 mm track envelope — inertia that the drive must accelerate on every index of the cam 12 mm pin bore and only 57 g: the smallest sizes demand accurate shaft geometry, because the 10.0 mm section leaves no tolerance for a soft or tapered seat C 9 kN and C0 10.4 kN already account for outer-ring bending between supports; the limiting speed is 4,500 r/min with no reference speed given STO is the basic yoke-type track roller with inner ring and without axial guidance: it runs on a normal-tolerance pin through its 12 mm bore Typical applications include printing press sheet-transfer grippers, glass and ceramic line conveyors and cam drives and indexing tables, where the 32 mm track diameter and 9 kN dynamic rating match the duty. In printing press sheet-transfer grippers the unit fits a compact 12 mm seat, and in glass and ceramic line conveyors the 57 g mass keeps follower kinetics light. Designers also specify it for cam drives and indexing tables, relying on the 11.8 mm width and the published 10.4 kN static rating. Check the mating track hardness and flatness — a soft or scalloped rail fails before the 32 mm outer ring does. Sealed PP/2RSR units are greased for life: never add a grease nipple, and respect the lower limiting speed imposed by the rubbing lips.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Check the mating track hardness and flatness — a soft or scalloped rail fails before the 32 mm outer ring does.
• 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.