Slick Drill Collars for Hole Drilling - Specification: 79.4mm - 279.4mm
API7-1 Drill Collars/Non-Magnetic Drill Collar Spiral Drill Collar Nmdc
Slick/Spiral Drill Collar API 7-1 Drill String Oilfield Downhole Equipment Non-Magnetic Drill Tools
Heavy Duty Slick Drill Collar for Reliable Drilling Machine Operations