Rust Grades, steel substrate before application of paints

Rust Grades

BS 7079 Pt A, ISO 8501, SS 05 59 00

    Preparation of steel substrate before application of paints and related products.
  1. Rust Grade A -

    • Steel surface largely covered with adherent millscale with little if any rust.
  2. Rust Grade B -

    • Steel surface, which has begun to rust and from which the millscale has begun to flake.
  3. Rust Grade C -

    • Steel surface on which the millscale has rusted away or from which it can be scraped, but with slight pitting visible under normal vision.
  4. Rust Grade D -

    • Steel surface on which the millscale has rusted away and on which general pitting is visible under normal vision.