... , Isuzu, Mazda, Buick, Peugeot, Daewoo, Kia, Renault, Citroen,Volkswagen,Mercedes-Benz, BMW, Audi, Volvo, Opel, Hyundai, Skoka, Lada, Fiat, Alfa etc ... by friction welding wherein high hot hardness alloy steel is used at head and stem made from a upright mechanical properties steel ...