... API inserts are mainly used for machinning the threads of oil pipes. Our Carbide API chasers are used for machining casings ... , tubings, leadout pipes, drill rod connectors, oil suching rods, separators, V-thread and buttress thread for oil industry as well as gas thread ... CNC machines.As a majore and professional manufacturer of carbide oil threading inserts in China, we can offer you a complete ...