API 7-1 non-magnetic drill collar Specifications 1.standard:API7-1 2.OD:79.4mm-279.4mm 3.factory directly delivery   API 7-1 non-magnetic drill collar Drill collars is one of the most important product of hexin oil drillings which mainly used to provide bit weight to...

API 7-1 Standard Drill Collar Specifications 1.standard:API7-1 2.OD:79.4mm-279.4mm 3.factory directly delivery   API 7-1 Standard Drill Collar Drill collars is one of the most important product of hexin oil drillings which mainly used to provide bit weight to drill so...

9 3/4" API Drill Collar Specifications 1.standard:API7-1 2.OD:79.4mm-279.4mm 3.factory directly delivery   9 3/4" API Drill Collar Drill collars is one of the most important product of hexin oil drillings which mainly used to provide bit weight to drill so...

Spiral drill collar Specifications 1.standard:API7-1 2.OD:79.4mm-279.4mm 3.factory directly delivery  Spiral drill collar  Drill collars is one of the most important product of hexin oil drillings which mainly used to provide bit weight to drill so that drill...

API Spiral drill collar Specifications 1.standard:API7-1 2.OD:79.4mm-279.4mm 3.factory directly delivery   API Spiral drill collar  Drill collars is one of the most important product of hexin oil drillings which mainly used to provide bit weight to drill so that...

3 1/8" Spiral Drill Collars Specifications 1.standard:API7-1 2.OD:79.4mm-279.4mm 3.factory directly delivery    3 1/8" Spiral Drill Collars  Drill collars is one of the most important product of hexin oil drillings which mainly used to provide bit...

2012 Best-selling drill collar Specifications 1.standard:API7-1 2.OD:79.4mm-279.4mm 3.factory directly delivery     2012 Best-selling drill collar Drill collars is one of the most important product of hexin oil drillings which mainly used to provide bit...