Rust on a steel surface is graded based on its severity. The grade affects the structural strength and the need for remediation.
Parameters:
(1) mill scale
(2) visible rust
(3) pitting
|
Mill Scale
|
Visible Rust
|
Pitting
|
Severity
|
Grade
|
|
adherent covering
|
minimal, questionable
|
none
|
minimal
|
A
|
|
flaking off
|
definite
|
none seen with naked eye
|
mild
|
B
|
|
mostly gone or easily scraped off
|
definite
|
little visible to naked eye
|
moderate
|
C
|
|
NA
|
extensive
|
extensive
|
maximum
|
D
|
where:
• There may be room for a Grade E where the steel is falling apart.
