Why ceramic breaks glass

When thrown with moderate speed at a side window, a sharp shard of the exceptionally hard aluminium oxide ceramic used in spark plugs focuses the impact energy into a small enough area without blunting to initiate cracking, releasing the internal energy and shattering the glass.

Re: Part of spark plug fell into cylinder The bits will bounce around, turn to dust and go out the exhaust valve. A growing trend in the automotive culture is applying a ceramic coating on glass — including windshields and rear windows.

To break your ceramic, place the item in a paper bag, then lightly tap the object with a hammer until you hear it has broken. Carefully remove the pieces from the bag.

Now, take your small piece of sharp porcelain and throw it at the center of the side car window as hard as you can. Even though you are not generating much force with your throw, the sharp porcelain point focuses the force. It should cause a tiny fracture in the tempered auto glass, which will instantly spread out. Extreme Hardness Surpassing that of Metals The hardness of alumina ceramics is nearly three times that of stainless steel; silicon carbide is more than four times harder than stainless steel.

Car windows are made from tempered glass and are designed to resist blunt force. As such, pounding on a window with a blunt object may have no effect.

There four types of glass which have varying impact resistance: Annealed glass, i. Golf balls, baseballs, and sometimes footballs will break and shatter it too. Anyway, race spark plugs sometimes need to be warmed properly to work OK. At the same time you are warming up the engine, all the system is doing the same, what includes spark plugs. Then again, these ceramic stones — which could also come from other ceramic products — can also be used for good.

For example, you could be locked out of your car and need to get inside to take something that could save your life such as medicine. Plus, the scariest scenario of all: The car could be on fire and someone is locked inside. Connect with us. Share Tweet Flip Send React.

View Comments. Although effective, spark plug fragments will not work all the time. Spark plug fragments may not break glass if they are not sharp enough or thrown with too little force. Spark plug porcelain shards are also less effective on windshields because these come with a special laminate feature that reinforces their resistance to impact. In some states, broken shards of spark plugs are considered a weapon. This is because they are sometimes used by burglars to break into vehicles.