Can anyone tell if these bearings load ratings are for a radial load or an axial load ?

Bearing designed for an axial load is (sometimes?) called a "thrust bearing".

Based on its mounting, I guess this is a thrust bearing for an axial load.

https://pgnbearings.com/collections/ucf200/products/ucf206-20-pillow-block-square-flange-mounted-bearing-1-1-4-bore ( those links work at time of posting )

Based on its mounting, I guess this is for a radial load.


The basic specifications are given in a table and include static and dynamic load ratings (images include a detailed mechanical drawing).

The mechanical drawing may indicate how the bearings are situated within the mounting.

For someone with more knowledge the mechanical drawing may allow you to determine if the bearing is designed for an axial or radial load.

-- EDIT --

After jko answered I looked again at the mechianal drawings provided in the specifications, for illustration here is another bearing


appears to be a radial bearing meaning designed to bear a load perpendicular to the axle on which it is mounted.

As I understand it the bearing balls themselves are mounted (inside the casing, if any, of the overall bearing ) on two surfaces, those surfaces determine how the bearing is designed to carry a load, the surfaces are perpendicular to the direction of load, or one could say the load is applied to those surfaces

in my original question as i look more closesly at the mechanical drawings provided in the specs, i now see the surfaces on which the ball bearings themselves roll appear to be perpendicular to the axis on which the bearing is mounted meaning both are thrust bearings

in the link in this comment, in the mechanical drawing the surfaces on which the bearing balls roll are parallel to the axis of the bearing so that this would be a radial bearing.

This isn't an attempt to answer my question but giving my own understanding and also a comment directed towards those who may have already answered asking for clarification.


1 Answer 1


That is a radial bearing, as shown in the section view in the drawing. Pillow blocks are typically radial bearings.

  • $\begingroup$ thank for your answer ive edited my question as my comment to you would be too long to fit here ... looking at the mechanical drawing to me it now seems both would be thrust bearings, can you clarify? $\endgroup$
    – kinidkinid
    Commented Apr 27, 2020 at 20:46
  • $\begingroup$ If you draw a line from the point of contact on the outer race of the bearing to the point of contact on the inner race, it is perpendicular to the axis of revolution for all 3 bearings you linked. This is the definition of a radial bearing, not thrust. For thrust bearings, the line of contact between races is parallel to the axis of revolution. The wikipedia article on bearings does an adequate job explaining all the variations in between. $\endgroup$
    – jko
    Commented Apr 28, 2020 at 12:30
  • $\begingroup$ jko ive annotated the mechanical drawing of the first linked bearing, showing the line of contact and the axis of revolution, i believe they are parallel imgur.com/gallery/d3uQYUO $\endgroup$
    – kinidkinid
    Commented Apr 28, 2020 at 18:16
  • $\begingroup$ @kinidkinid that is not the line of contact of that bearing, this link provides a more clear drawing: cad.timken.com/item/all-product-types/ucp-pillow-block-units/… $\endgroup$
    – jko
    Commented Apr 28, 2020 at 18:22
  • $\begingroup$ it appears in your annotations you've highlighted the grooves for a seal, the races have concavity that is nearly identical to the curvature of the rolling elements. You'll see there is one inner ring that goes around the shaft and one outer ring that is in the pillow block housing. $\endgroup$
    – jko
    Commented Apr 28, 2020 at 18:24

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