STO-12 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 15 support rollers / ch. 16 cam followers) · extracted 2026-09-30

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 15 support rollers / ch. 16 cam followers); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.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 STO-12 model number is decoded

the 32 mm outside diameter runs on the track while the 12 mm bore takes the pin or shaft; the 12 mm overall width spreads the Hertzian contact over the outer ring published ratings C 8.8 kN and C0 9.8 kN already include the bending-stress correction for the unsupported outer ring — the C/C0 ratio of 0.90 is typical for support roller without flange rings, with inner ring executions fatigue load limit Pu 1.18 kN at 12 mm bore gives a specific load of 0.73 kN per mm; the limiting speed is 5,600 r/min the 12 mm width carries the load at 0.73 kN per mm of roller complement; section height 10.0 mm between bore and track surface determines the outer-ring bending stiffness mass 57 g over a 32x12 mm envelope works out to 0.148 g per mm² of projected area — a useful figure when sizing the drive inertia for medium-high-speed cam duty at 12 mm bore this size balances load capacity and envelope compactness — a frequent pick for packaging machines and printing press linkages STO is the entry-level support roller execution: no integral flanges or seals, so the designer must provide axial location and contamination protection in the surrounding structure typical applications include printing press roller followers, automotive welding jig positioners and conveyor transfer and diverting rollers this size is commonly specified for printing press roller followers and automotive welding jig positioners, where the 32 mm track diameter and 12 mm bore fit standard cam and rail geometries in conveyor transfer and diverting rollers the 32 mm outer ring provides the rolling contact while the inner ring bore simplifies mounting; the 57 g mass is low enough for rapid indexing cycles the open design has no integral sealing; in dusty environments contamination enters directly between the needle rollers and the raceway mounting on a worn or undersized pin reduces the effective clearance and can preload the roller hot

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• without integral flanges, axial float must be controlled by external washers or circlips — free axial movement causes edge loading on the outer ring
• the open design has no integral sealing; in dusty environments contamination enters directly between the needle rollers and the raceway
• the needle roller complement is sensitive to misalignment; a bent shaft or angled track creates uneven load distribution and early raceway pitting