NATR-20-PPA 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 NATR-20-PPA model number is decoded

the 47 mm outside diameter runs on the track while the 20 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 24.5 kN already include the bending-stress correction for the unsupported outer ring — the C/C0 ratio of 0.60 is typical for support roller with flange rings, with inner ring executions fatigue load limit Pu 2.9 kN at 20 mm bore gives a specific load of 0.73 kN per mm; the limiting speed is 3,000 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 240 g over a 47x25 mm envelope works out to 0.204 g per mm² of projected area — a useful figure when sizing the drive inertia for medium-speed cam duty at 20 mm bore this size balances load capacity and envelope compactness — a frequent pick for packaging machines and printing press linkages the NATR execution is the caged, flanged variant — cage guidance gives a higher limiting speed than the full-complement NATV, while the flanges simplify housing design by eliminating separate thrust faces the PPA variant has a crowned track surface: the 47 mm OD is finished with a large-radius crown that compensates for minor track misalignment and reduces edge stress concentration typical applications include glass processing line conveyors, linear guide and track systems and robotic arm track guidance this size is commonly specified for glass processing line conveyors and linear guide and track systems, where the 47 mm track diameter and 20 mm bore fit standard cam and rail geometries in robotic arm track guidance the 47 mm outer ring provides the rolling contact while the inner ring bore simplifies mounting; the 240 g mass is low enough for rapid indexing cycles 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

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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 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
• the cage material is typically polyamide or steel; at temperatures above 100 degC polyamide cages soften and lose guidance function