... :120.7 127.0 158.8 165.1 177.8 Drill Collar can be produced according to APi standard,as well sa ... of perfect anti-sticking nature. Our factory has the largest drill in n orthern China, joint production line, has been certified ... a number of CNC lathes, special testing equipment, manufacture of drill pipe to meet the geological, geothermal, wells, oil drilling and ...