We use our in house high precision SERDI valve seat cutting machine to cut all the angles (i.e. 30, 45 and 60 degrees) of a valve seat at the same time with one pass using a carbide cutter. What makes the SERDI so accurate is its ability to float on air to find the true center in the valve seat to perfectly align the pilot before the cutting begins. This is the only process to ensure an accurate valve seat match. We then check the precision work with a concentricity gauge to ensure the best performance.