NATR-40-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-40-PPA model number is decoded

the 80 mm outside diameter runs on the track while the 40 mm bore takes the pin or shaft; the 32 mm overall width spreads the Hertzian contact over the outer ring published ratings C 31.9 kN and C0 57 kN already include the bending-stress correction for the unsupported outer ring — the C/C0 ratio of 0.56 is typical for support roller with flange rings, with inner ring executions fatigue load limit Pu 7.1 kN at 40 mm bore gives a specific load of 0.80 kN per mm; the limiting speed is 1,500 r/min the 32 mm width carries the load at 1.00 kN per mm of roller complement; section height 20.0 mm between bore and track surface determines the outer-ring bending stiffness mass 800 g over a 80x32 mm envelope works out to 0.313 g per mm² of projected area — a useful figure when sizing the drive inertia for low-speed cam duty the 40 mm bore places this in the medium band, where cylindrical-roller full-complement designs become available for heavier radial loads 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 80 mm OD is finished with a large-radius crown that compensates for minor track misalignment and reduces edge stress concentration typical applications include robotic arm track guidance, paper mill web guide rollers and automatic assembly machine linkages this size is commonly specified for robotic arm track guidance and paper mill web guide rollers, where the 80 mm track diameter and 40 mm bore fit standard cam and rail geometries in automatic assembly machine linkages the 80 mm outer ring provides the rolling contact while the inner ring bore simplifies mounting; the 800 g mass is low enough for rapid indexing cycles 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

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• the pressed-on flange rings are not designed for continuous axial load — side thrust from a skewed track will eventually dislodge them
• the flange rings are a press fit on the inner ring; excessive axial preload during mounting can shift them and alter the internal clearance
• 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