... High erosion endurance, High concussion endurance. intake & exhaust valve. High attrition endurance, High temperature endurance, High erosion endurance, ... material: INLET VALVE IS SUH3(4Cr9Si2) ; EXHAUST VALVE IS SUH35(21-4N), normal material: INLET VALVE IS SUH1(40Cr) ; EXHAUST VALVE IS SUH3 ... AND SO ON.4. We have all kinds of valve techniques, entire material valves, double metal friction welding , ...