AISI 4145h Oil Drilling Heavy Weight Drill Rod/Drill Pipe O. D 88.9mm with API Spec 7-1 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Oil/Gas/Water Drilling Heavy Weight Drill Rod/Drill Pipe O. D 88.9mm with API Spec 7-1 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Water Well Drilling Drill Collar 203.2mm-Nc56 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Oil/Gas/Water Drilling Drill Collar 203.2mm-Nc56 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Oil Drilling Drill Collar 203.2mm-Nc56 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Water Well Drilling Drill Collar 177.8mm-Nc50 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Oil/Gas/Water Drilling Drill Collar 177.8mm-Nc50 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Oil Drilling Drill Collar 177.8mm-Nc50 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Water Well Drilling Drill Collar 165.1mm-Nc46 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. AISI 4145h Oil/Gas/Water Drilling Drill Collar 165.1mm-Nc46 with API Spec 7-1/7-2 Hebei Shitan Machinery Manufacturing Co., Ltd. <<<2021222324>>>