3D Surface Roughness and Wear Measurement, Analysis and Inspection

Stylus Rz Ratio

Stylus X Rz/Stylus Y Rz

The various Stylus X/Stylus Y ratios are found by dividing the corresponding Stylus X parameter (e.g., Stylus X Rz) by the corresponding Stylus Y Parameter (e.g., Stylus Y Rz). Thus the various ratios are unitless quantities.

A lathe- turned surface (A) for which Stylus X Ra/Stylus Y Ra is about 2.5 and a peened surface (B) where Stylus X λq/Stylus Y λq is about 1.0.


The ratio of the various Stylus X and Stylus Y parameters demonstrates the spatial isotropy of the surface texture. For example, the lathe-turned surface (Figure A) has a high degree of anisotropy and thus the ratio of Stylus X Ra/Stylus Y Ra is greater than 1.00. A shot peened isotropic surface will tend to have Stylus X and Y ratios of about 1.00. The ratios may be used to assess the ability for a given surface finishing operation to remove remnants of a previous operation. The ratios may also be used to uncover any dominant surface directional paths that may contribute to fluid leakage.

See Also:

Stylus Pc Ratio

Stylus Ra Ratio

Stylus Δq Ratio

Stylus λq Ratio