Bearing Stress 1

[DBCox]

Hello everyone,

Is there a way to estimate the allowable bearing stress of a metal if the typical properties (UTS, YS, E, ect.) are known? I know the bearing stress is usually much higher than the yield, and a little higher than the UTS, but I would like to know for sure.

If this is not possible, where can I find this information? I cannot find it in my usual material properties sources.

Thanks

 

[israelkk]

MIL-HDBK-5

 

[electricpete]

just to clarify - rolling bearing or sleeve?

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[vonlueke]

blakrapter: For isotropic metals, in the absence of published bearing strength values, bearing yield strength can be approximated as Sbry = 1.5*Sty and bearing ultimate strength can be approximated as Sbru = 1.5*Stu, provided you have edge distance of 2.0*D or more, where Sty = tensile yield strength, and Stu = tensile ultimate strength.

 

[DBCox]

Cool, thanks for the info everyone!

 

[vonlueke]

electricpete: Bearing strength (stress), in the sense used above, is the resistance to excessive elongation deformation or rupture by crushing of a circular hole in a flat plate when force is applied to the inside of the hole by a cylindrical fastener loaded in shear (force applied parallel to the plate). Edge distance, e, is measured from the hole centerpoint to the edge of the plate in the direction of the applied shear load.

 

[Lcubed]

blakrapter,
The info above is good for the condition defined by vonlueke. That kind of 'bearing strength' is largely empirical and is not a true Hertzian bearing strength. If you are concerned with any other kind of bearing, i. e., any kind of part bearing against any other part, the allowable usually depends upon design requirements. That is, bearing companies do not want spalling or other fatigue damage; railroads may be concerned with other kinds of failure, etc. Permanent set occurs, theoretically, at about 1.81 times TENSILE yield strength of the material, where stress is calculated by Hertz' methods. Hope this helps.