Detailed Product Description zhejiang minghe steel pipe co., ltd is one of the largest seamless steel pipe manufactures in China with API 5L , API 5CT certification and ISO quality system certification.commodity:API 5L LINE PIPEOD: 4 1/2"- 8 5/8"WT:6-50mmStandard:API 5LGrade:A25, A, B, X42, X52