NATR-25 bearing: complete specifications & equivalents

The NATR-25 is a ISO 15 radial bearing sized 25 x 52 x 25 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 = 52 mm d = 25 B = 25 mm side section front view
Principal dimensions: bore d 25 mm, outer diameter D 52 mm, width B 25 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand SKF
Bore diameter d 25 mm
Outer diameter D 52 mm
Width B 25 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage steel
Basic dynamic load rating C 14.7 kN
Basic static load rating C0 25.5 kN
Fatigue load limit Pu 3.1 kN
Limiting speed (mechanical) 2400 rpm
Operating temperature -40 to +120 °C
Mass 280 g
Manufacturer designation NATR 25
Standard ISO 15
Catalog version SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 15 support rollers / ch. 16 cam followers
Last verified 2026-09-30

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.

Dimensions in inches & NATR-series range

Bore d 0.984 in
Outer diameter D 2.047 in
Width B 0.984 in
ISO bore code —
Radial section height (D−d)/2 13.5 mm
Smallest bore in NATR-series 5 mm
Largest outer diameter in NATR-series 90 mm
Width range across NATR-series 12–32 mm
Bore position in NATR-series (smallest first) 9 of 13
Bore above smallest NATR-series size 20 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
NATR 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 NATR-25 model number is decoded

the 52 mm outside diameter runs on the track while the 25 mm bore takes the pin or shaft; the 25 mm overall width spreads the Hertzian contact over the outer ring published ratings C 14.7 kN and C0 25.5 kN already include the bending-stress correction for the unsupported outer ring — the C/C0 ratio of 0.58 is typical for support roller with flange rings, with inner ring executions fatigue load limit Pu 3.1 kN at 25 mm bore gives a specific load of 0.59 kN per mm; the limiting speed is 2,400 r/min the 25 mm width carries the load at 0.59 kN per mm of roller complement; section height 13.5 mm between bore and track surface determines the outer-ring bending stiffness mass 280 g over a 52x25 mm envelope works out to 0.215 g per mm² of projected area — a useful figure when sizing the drive inertia for medium-speed cam duty the 25 mm bore puts this in the small-to-medium transition where the roller complement is still needle-type but the outer ring is thick enough for moderate shock loads NATR adds pressed-on flange rings to the basic support roller; these locate the roller axially and absorb light side thrust, but they are not designed for continuous axial load typical applications include paper mill web guide rollers, automatic assembly machine linkages and food processing line track rollers this size is commonly specified for paper mill web guide rollers and automatic assembly machine linkages, where the 52 mm track diameter and 25 mm bore fit standard cam and rail geometries in food processing line track rollers the 52 mm outer ring provides the rolling contact while the inner ring bore simplifies mounting; the 280 g mass is low enough for rapid indexing cycles cage guidance (NATR) is less tolerant of shock than full complement (NATV); heavy impact can crack the cage and release rollers into the mechanism the flange rings are a press fit on the inner ring; excessive axial preload during mounting can shift them and alter the internal clearance

Typical equipment & failure modes

Common applications

  • woodworking machinery feed rollers
  • paper mill web guide rollers
  • cam mechanisms and indexing drives
  • material handling lift and lower tracks

Known failure patterns

  • the pressed-on flange rings are not designed for continuous axial load — side thrust from a skewed track will eventually dislodge them
  • the flanges reduce the available track width by their own thickness; check the cam channel width against the B dimension, not just the outer ring width
  • cage guidance (NATR) is less tolerant of shock than full complement (NATV); heavy impact can crack the cage and release rollers into the mechanism
  • the flange rings are a press fit on the inner ring; excessive axial preload during mounting can shift them and alter the internal clearance
  • do not use the flange faces as thrust surfaces for external components — the pressed joint is designed for guidance, not for transmitting axial force
  • the cage material is typically polyamide or steel; at temperatures above 100 degC polyamide cages soften and lose guidance function

Selection pitfalls — read before you substitute

  • the cage material is typically polyamide or steel; at temperatures above 100 degC polyamide cages soften and lose guidance function
  • cage guidance (NATR) is less tolerant of shock than full complement (NATV); heavy impact can crack the cage and release rollers into the mechanism
  • the pressed-on flange rings are not designed for continuous axial load — side thrust from a skewed track will eventually dislodge them

Frequently asked questions

What are the dimensions of the NATR-25?

NATR-25 is a support roller with flange rings, with inner ring with 52 mm outside diameter, 25 mm bore diameter and 25 mm overall width. The bore is 25 mm and the track contact diameter is 52 mm.

What does the NATR designation mean?

The NATR prefix identifies this as a support roller with flange rings, with inner ring. In the SKF catalogue this designation carries the full specification including the 52x25x25 mm envelope and the 2400 r/min limiting speed.

What is the load capacity of NATR-25?

The published basic dynamic load rating C is 14.7 kN and the basic static load rating C0 is 25.5 kN. These values already include the bending-stress correction for the thick-walled outer ring running on a track.

Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 15 support rollers / ch. 16 cam followers on 2026-09-30. Read our editorial & correction policy.