ISO 3075: International Organization for Standardization standard for "Short Link Chains for Lifting - Grade T(8)". G80 corresponds to Grade T(8).
ASME B29.10: American Society of Mechanical Engineers standard, which clearly specifies the material, dimensions, tolerances, testing, and marking requirements for G80 chains.
DIN 5687-8: German Industrial Standard.
GB/T 20946: Chinese National Standard "Short Link Chains for Lifting - General Acceptance Rules" Grade 8, equivalent to G80.