Flatness
Glossary · Tolerance & Measurement
At a glance
- Category /
- Tolerance & Measurement
- Related /
- 2 terms
- Source /
- Written in the shop
Flatness controls how much a surface may deviate from a perfect plane, independent of any other feature on the part.
In practice
Flatness is measured as the gap between two imaginary parallel planes that just contain the whole surface. It needs no datum, because it says nothing about orientation — only about the surface itself.
Why it matters
Flatness is what decides whether a gasketed joint seals or a mounted component sits without being stressed into distortion when the bolts are pulled down.
More in Tolerance & Measurement
Have a drawing with this on it?
Request a Quote
Send it over and we will tell you what it will take to hold — and what is safe to loosen.