A welding torch comprising: a main cylindrical conductive assembly with a front diffuser section having a plurality of circumferentially spaced shielding gas diffuser orifices for directing shielding gas radially outwardly from the assembly, a forwardly facing threaded bore extending through a cylindrical support nose and an elongated wire passageway coaxial with the threaded bore and opening at the rear end of the assembly. An insulated, cylindrical protective sleeve fitted around both the support nose and the diffuser orifices where the sleeve has a front clearance opening and circumferentially spaced openings communicated with the diffuser orifices and a contact tip having a central wire guide bore with a diameter only slightly larger than the diameter of the welding wire, a threaded rear body, a front extension passing through the front clearance opening and a radially extending flange between the rear body and the front extension to hold the protective sleeve around the nose when the body is screwed into the threaded bore of the main assembly.