Arithmetic mean roughness of the flank

Symbol Ra
Unit µm
Attribute-ID arithmetic mean flank roughness
Numeric ID 367
Value Type PMTechValue

The arithmetic mean of the absolute values for profile variation within the measuring area lm. [Fischer, U. et. al.: Tabellenbuch Metall; Europa-Lehrmittel, 41st edition]  (in German)

Z z axis
m Reference line
lm Measurement area
Ra Arithmetic mean roughness value

Ra can be approximately converted to Rz using the following equation: Ra = Rz / 6

Rz can be approximately converted to Ra using the following equation: Rz = Ra * 6