Blackening treatment is commonly used for G80-grade high-strength lifting chains. • Strength grade: The most common grade is G80 (T8); G80 indicates that the chain can withstand a tensile force of 80 N per square millimeter. • Manufacturing standards: These chains comply with international standards such as ISO3077, EN818, AS2321, as well as national standards like GB/T24816-2017. • Safety performance: The safety factor is usually 4 times, with the test load being 2.5 times the rated load. • Specifications and materials: The diameter ranges from 5 mm to 32 mm, and the materials are mostly alloy steels (such as manganese steel and 20Mn2A).