Cutting torch ---- is the main tool of gas cutting, also known as cutting gun. The main function is to mix the combustible gas and oxygen in the cutting torch to form a preheating flame with certain heat energy and shape, and spray high-pressure oxygen flow at the center of the preheating flame for gas cutting.

Backfire ---- the flame instantly reverses to the cutting nozzle of the cutting torch. At this time, leave the cutting nozzle from the workpiece, and the gas may burn again, but sometimes it can only burn with the help of a lighter.

Flashback ---- when the injection speed of mixed gas is less than the combustion speed, that is, the injection speed is too slow, so that the ignited flame cannot burn outside, and the flame will quickly fall back into the welding and cutting torch and rubber tube. Therefore, the scene of flame backflow is called tempering. When tempering occurs, there will be "hissing" sound or scream and obvious smoke.