scope:

The present standard will help in making a better evaluation of the surface roughness of the active area of the tooth flank and tooth fillet. It will confine itself to the profile method, this being the method most frequently used in measuring gearing. Other methods can also be used as well as this one, such as scanning electron microscopy, scatteredlight and optical-interference methods. Comparability of the measurement results from the various methods cannot however be assumed.

Tolerancing information for the toothing accuracy classes according to DIN 21771 do not include any requirements relating to surface roughness. Where necessary these should be defined and can, as indicated in DIN EN ISO 1302, be added to the drawing.