Roughness question

Rmax - Maximum Height of Profile
Highest peak to valley within a sampling length. When measured over several sampling lengths the largest individual sampling length value is taken.
Rmax is a controlling parameter, particularly useful where components are subjected to high stresses, any large peak to valley could suffer from crack propagation.
Singular large peaks can also penetrate oil lubrication films increasing wear , debris and damage to sliding surfaces.



Ry - Maximum Height of Profile
Highest peak to valley within a sampling length measured over minimum of two sampling lengths - the largest individual sampling length value is taken.
Ry (pre 1997) is a controlling parameter, useful where components are subjected to high stresses, any large peak to valley could suffer from crack propagation.
In this non standard Industrial definition there was only a two Sampling Length minimum.
Singular large peaks can also penetrate oil lubrication films increasing wear , debris and damage to sliding surfaces.
The current equivalent Rz1max recommends a minimum of 5 Sampling Lengths giving better stability.
See Rz1max and Rt.

Rmax - Maximum Height of Profile
Highest peak to valley within a sampling length. When measured over several sampling lengths the largest individual sampling length value is taken.
Rmax is a controlling parameter, particularly useful where components are subjected to high stresses, any large peak to valley could suffer from crack propagation.
Singular large peaks can also penetrate oil lubrication films increasing wear , debris and damage to sliding surfaces.



Ry - Maximum Height of Profile
Highest peak to valley within a sampling length measured over minimum of two sampling lengths - the largest individual sampling length value is taken.
Ry (pre 1997) is a controlling parameter, useful where components are subjected to high stresses, any large peak to valley could suffer from crack propagation.
In this non standard Industrial definition there was only a two Sampling Length minimum.
Singular large peaks can also penetrate oil lubrication films increasing wear , debris and damage to sliding surfaces.
The current equivalent Rz1max recommends a minimum of 5 Sampling Lengths giving better stability.
See Rz1max and Rt.