Grading evaluation of non-API OCTG quality level based on working conditions Mengfei Xu, Chun Feng, Lijuan Zhu, Shidong Zhu and Lei He Int. J. Metrol. Qual. Eng., 14 (2023) 8 Published online: 05 July 2023 DOI: 10.1051/ijmqe/2023006