Rz (maximum height of profile)
Sum of the highest peak and deepest valley of the roughness profile within the evaluated section.
Theoretical peak-to-valley height in turning is about f squared divided by (8 times the nose radius), roughly four times the theoretical Ra. Real values are higher.
General shop guidance in our own words. The drawing and the standard it cites decide; verify on a sample part.
Typical finish by process and the turning feed and nose-radius formula: Surface finish guide.
Related surface roughness parameters
Tell the advisor the feature, the tolerance on the drawing and the material. It answers with machining choices, brand-neutral.
Definition written in our own words and checked against engineersedge.com. Symbol and term names follow ISO 21920-2; we do not reproduce standard text. See the full index.