点火孔是一个小孔，通过它可点燃加农炮或前膛枪的推进剂。

A touch hole, also called a vent, is a small hole near the breech of a cannon or muzzleloading gun through which the propellant charge is ignited. In small arms, the flash from a charge of priming held in the flash pan is enough to ignite the charge within. In artillery, priming powder, a fuse, squib, or friction igniter is inserted into the touch hole to ensure ignition of the charge.