First, suitable for use: all kinds of angles in 18-62mm valve can be used; Optional steel plate Two, a molding: working face and upper and lower chamfering a processing; Three, no grinding: the valve seat ring after processing generally does not need grinding, can be used directly with the new valve; Four, accurate positioning: ensure the valve seat working face Angle, the position of the upper and lower chamfer, width and coaxiality with the valve guide; Five use: the reamer blade with blunt…