ASTM A240 is the material standard for chromium-nickel stainless steel plate, sheet, and strip for pressure vessels and general applications; A480 covers general delivery requirements (dimensions, surface, flatness, tolerances, test methods).

In practice, contracts often state "A240/A480"—both are indispensable: - A240 defines grade composition and mechanical properties. - A480 defines thickness tolerances, surface finishes, flatness, and packaging.

Note: A480 has multiple surface designations (No.1, 2D, 2B, BA, No.4, No.8), which must be clearly specified when ordering.