Aluminium Oxide Ceramic Spark Plug
Though various materials have been used for spark plug insulators through the years the current contender is aluminum oxide.
Aluminium oxide ceramic spark plug. Federal mogul corp a southfield mich based supplier of oem and aftermarket automotive components and systems has introduced a new high performance spark plug featuring a high alumina insulator material that enables the plug to handle the increasing thermal voltage and other requirements of modern high output gasoline engines. This modern day insulator provides many benefits over previous designs including superior insulation or thermal conductivity. Most spark plugs now use a 1 piece ceramic insulator made from purified alumina powder. The electrodes in a spark plug typically consist of high nickel alloys while the insulator is generally made of aluminum oxide ceramic and the shell is made of steel wire.
Ninja rocks are broken shards of spark plugs that are formed by smashing the ceramic portion of the spark plug with a hammer or other large object. Ceramic materials are used as insulators in spark plugs the ceramic material is placed between the main electrode and the spark plug body. Selection of materials for both the electrodes and the insulator have consumed much research and development time and cost. Since they can quickly and quietly fracture the glass side windows on most cars ninja rocks have been used in smash and grab auto burglaries since at least 1995.