Definition(s)
Stainless Steel
Steel containing more than 11 % mass fraction chromium to render the steel corrosion resistant. NOTE Other elements may be added to secure special properties.
Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards
Stainless Steel
Steel containing chromium, more than 11%, to render the steel corrosion resistant. Other elements may be added to secure special properties.
Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards