... J55, N80, P110 Our Carbide API Inserts are used for machining casings, tubings, leadout pipes, drill rod connectors, oil suching rods, separators ... and convenient clamping, finished teeth ground to a "narrow" API tolerance and excellent cutting performance.The multi-layer-coating inserts ... China, we can offer you a complete line of API threading Inserts for your application. Our customers are ranging ...