There are several measuring methods for determining the roughness depth. The two most common values are the average roughness depth (Rz) and the average roughness value (Ra). These are most frequently used when specifying surfaces. So far we have defined the surfaces according to Rz, from now on (12.09.2019) all newly created drawings should be made with the surface specification according to Ra.
Existing drawings will be changed if they are revised for other reasons.
Since Rz and Ra values are determined differently, they cannot be converted. The table DIN4768-1 is named as an aid for a reinterpretation. However, this table offers a large scatter range.
