... many countries.We have passed ISO 9001.2. Our engine valve kind is complete , the quality is frist-class, the price ... of material,the good and normal, good material: INLET VALVE IS SUH3(4Cr9Si2) ; EXHAUST VALVE IS SUH35(21-4N), normal material: INLET ... ,VOLKSWAGEN AND SO ON. 4. We have all kinds of valve techniques, entire material valves, double metal friction welding , small soldering ...