The flint is held in a clamp at the end of a bent lever called the cock. Upon pulling the trigger, this moves forward under the pressure of a strong spring and strikes a curved plate of hardened steel (called simply the steel, or in 17th century English dialect the frizzen) to produce a shower of sparks (actually white-hot steel shavings). These fall into a flash pan holding priming powder. The flash from the pan travels through the touch hole to cause the main charge of gunpowder to explode. The steel is at the end of an arm that can be moved independently of the pan cover.