Abstract: A fuel gas and oxygen mixer for a gas torch comprises a tubular body having a mixing passage extending therethrough and having an upstream end connected to sources of a fuel gas and oxygen and a downstream end for delivering a mixture of the fuel gas and oxygen to a torch tip. The fuel gas is axially supplied to the upstream end of the mixer, and the oxygen flows along the outer surface of the body in the upstream direction from a point adjacent the downstream end of the body and then into the mixing passage through radial ports adjacent to the upstream end of the body. The counter flow of oxygen is through a passageway which provides for cooling of the mixer during normal operation of the torch and for the quenching of reversely flowing hot gases during a back fire.