GB/T3094 standard specifies the classification, code, shape, size and tolerances of cold drawn profiled steel pipes, technical requirements, test methods, inspection rules, packaging, marking and quality certificates.GB/T3094 standard applies to carbon structural steel, high-quality carbon structural steel and low-alloy high-strength structural steel made of simple cross-section profile steel pipe.GB/T3094 Standard main steel grade:Q660,Q510,Q460D,Q460C,Q345E and so on.