... conform to API Spec 6A, the product adopts some end connections of pipeline thread, tubing thread, butt-weld ... connections of pipeline thread, tubing thread, butt-weld. Connections Type:Component Parts:Application: pipeline thread, tubing thread, butt-weld;Nut ... , Male Sub, Female Sub, Seal Ring;oil field equipmentShanghai Jefa Machinery Co.,Ltd specialize in API ...