Surface Roughness, Roughness, Waviness (metrology)



Surface Roughness
Every machine operation leaves a characteristics evidence on the machine surface. This evidence is in the form of finely spaced micro irregularities which are left by the cutting tool.
Each type of cutting tool leaves its own individual pattern is known as Surface Roughness.

Roughness:
It is known as Primary Texture
It consists of Surface irregularities which results from the various machining operations. These irregularities combine to form Surface Texture.

Roughness Height:
It is the height of the irregularities surface with the reference line. It is measured in microns

Roughness Width:
It is the distance parallel to the normal surface between successive peaks.

Waviness:
It is known as secondary Texture
It may be result of work piece or tool deflection during machining, vibrations or tool run out.

Waviness Height:
It is the height of irregular surface from Peak to Valley distance of the surface profile.

Roughness Width Cut-Off:
It is the greatest spacing of respective surface facing irregularities to  be included in the measurement of the average roughness height. It should always greater than the roughness width,

Form:
This is general shape of surface, ignoring variations due to roughness & waviness.