ISO Rust Grade Book specifies Rust Grades and Preparation Grades of blast-cleaned steel.

The Rust Book Grades are defined by written descriptions together with photographs.

The Rust Grade Book identifies four levels (designated as Rust Grades) of mill scale and rust that are commonly found on surfaces of uncoated erected steel and steel held in stock.  The Rust Grade Book also identifies certain degrees of visual cleanliness (designated as Preparation Grades) after surface preparation of uncoated steel surfaces and of steel surfaces after overall removal of any previous coating.

Compliant to ISO 8501-1.