A gas key is a mixture of pliers and an open-end wrench. When using it, the hexagonal profile of the nut is not required and it can work with round surfaces. By increasing the pressure on the handle of the key, the pressure of the jaws of the key and the magnitude of the moment force to the clamped part automatically increase. The disadvantage of a gas key is that it severely damages the contact with the metal surface. The gas wrench has less torque than the ring wrench. To work with different diameters of pipes and fittings, gas keys are available in various sizes. Models are marked by the angle of inclination of the jaws - 45 ° or 90 ° C.
Gas or pipe wrenches are used to provide a secure fit for threaded pipes and bolts.