RSTO12 bearing: complete specifications & equivalents

The RSTO12 is a ISO 15 radial bearing sized 16 x 32 x 11.8 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 32 mm d = 16 B = 11.8 mm side section front view
Principal dimensions: bore d 16 mm, outer diameter D 32 mm, width B 11.8 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand FAG
Bore diameter d 16 mm
Outer diameter D 32 mm
Width B 11.8 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage steel
Basic dynamic load rating C 9 kN
Basic static load rating C0 10.4 kN
Fatigue load limit Pu 1.56 kN
Limiting speed (mechanical) 4500 rpm
Operating temperature -40 to +120 °C
Mass 49 g
Manufacturer designation RSTO12
Standard ISO 15
Catalog version HR1 2026-09-25
Last verified 2026-09-30

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.

Dimensions in inches & rsto-series range

Bore d 0.63 in
Outer diameter D 1.26 in
Width B 0.465 in
ISO bore code —
Radial section height (D−d)/2 8 mm
Smallest bore in rsto-series 7 mm
Largest outer diameter in rsto-series 90 mm
Width range across rsto-series 7.8–19.8 mm
Bore position in rsto-series (smallest first) 5 of 14
Bore above smallest rsto-series size 9 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
RSTO12 ISO 15 full
Dimensions and internal design equivalent — standard interchange.
ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data.

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 RSTO12 model number is decoded

envelope 16×32×11.8 mm: the 32 mm outside diameter is the track-running surface — a thick-walled outer ring over a 16 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 RSTO yoke-type track roller without 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 8.0 mm radial section gives the outer ring its bending stiffness fatigue load limit Cur is 1.56 kN at 16 mm bore, equivalent to 0.56 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 16 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 49 g, or 0.13 g per mm² of the 32×11.8 mm track envelope — inertia that the drive must accelerate on every index of the cam the 16 mm pin bore falls in the small band, the workhorse size for gearbox planetary positions, hydraulic pumps and general cam and linkage duty With C 9 kN and C0 10.4 kN the roller accepts track loads directly; the 4,500 r/min limiting speed is the only speed figure HR1 publishes for track rollers Reading RSTO: yoke roller, no inner ring, no flanges; lateral guidance and contamination protection must come from the machine structure around the 11.8 mm-wide roller Typical applications include woodworking machine feed tracks, cam drives and indexing tables and packaging machine timing mechanisms, where the 32 mm track diameter and 9 kN dynamic rating match the duty. In woodworking machine feed tracks the unit fits a compact 16 mm seat, and in cam drives and indexing tables the 49 g mass keeps follower kinetics light. Designers also specify it for packaging machine timing mechanisms, relying on the 11.8 mm width and the published 10.4 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. Flangeless STO/RSTO/RNA22/NA22 rollers need external axial location; circlips or shoulders must control end float or the roller walks off the track.

Typical equipment & failure modes

Common applications

  • agricultural and textile cam followers
  • printing press sheet-transfer grippers
  • robotic arm linear axes
  • conveyor transfer and diverting stations

Known failure patterns

  • outer-ring fatigue cracking across the unsupported track zone under excessive static load
  • track-side brinelling when the mating rail is softer than the roller running surface
  • flat spots from standing loads or very short oscillating strokes on full-complement rollers
  • seal lip failure and grease loss after sustained running above the limiting speed (PP/2RSR executions)
  • edge wear from skewed tracks that exceed the crowned-profile correction range
  • pin-seat fretting where a hard journal requirement (RSTO/RNA22) was met with a soft pin
  • roller walk-off in flangeless STO/RSTO executions with uncontrolled lateral float
  • contamination entry through open sides in dusty or wash-down environments
  • cage fracture in caged NATR/STO rollers exposed to heavy shock

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.
  • Flangeless STO/RSTO/RNA22/NA22 rollers need external axial location; circlips or shoulders must control end float or the roller walks off the track.
  • The crowned outer profile tolerates only small skew; a track that departs by more than the catalogue angle still causes edge loading.

Frequently asked questions

What are the dimensions of the RSTO12?

The RSTO12 is a RSTO yoke-type track roller without inner ring, without axial guidance with 32 mm outside diameter, 16 mm bore and 11.8 mm width, envelope 16×32×11.8 mm. Mass is 49 g.

What does the RSTO12 designation mean in the FAG/INA HR1 catalogue?

RSTO12 identifies this RSTO yoke-type track roller without inner ring, without axial guidance in the Schaeffler HR1 rolling bearings catalogue. The envelope is 16×32×11.8 mm and the catalogue ratings are C 9 kN, C0 10.4 kN, Cur 1.56 kN.

What is the load capacity of the RSTO12?

The basic dynamic load rating C is 9 kN and the basic static load rating C0 is 10.4 kN; the fatigue load limit Cur is 1.56 kN. For track rollers these values already cover the thick-walled outer ring bending case on an unsupported track.

What is the maximum speed of the RSTO12?

HR1 lists a limiting speed of 4,500 r/min for track rollers and no thermal reference speed. The crowned thick-walled outer ring and (on stud types) the stud contact make the limiting speed the governing figure.

What must the mating track and pin look like for the RSTO12?

The track should be flat, harder than the roller contact and clean; the crowned 32 mm outer surface tolerates only small angular error. The 16 mm pin must be hardened to 58–64 HRC and ground like a raceway; lateral guidance comes from the adjacent structure on flangeless executions.

Reviewed & verified by the MPN Base engineering desk against source catalog HR1 2026-09-25 on 2026-09-30. Read our editorial & correction policy.