First the spindles/seats are analysed to know what kind of base materials are used. This will determine the welding procedure

All burned/worn layers are machined off and rewarded on automatic welding machines. 

Final machining takes place on CNC controlled turning machine to meet the original tolerances specified by the engine builder. 

After machining a full measurement report is made, also the seating area/bottom side and fillet to stem is dye checked.