23 Series Self-Insulated Nozzle with 0.625" bore size is designed to use with up to 450 A Tweco® no.3 MIG guns and the nozzle strings into the conductor tube assembly. 3.219" Nozzle has a 0.875" OD and is used in heavy-duty welding applications for up to 450 A. It features part number rolled stamped on the outer surface for easy identification. Nozzle with 9/16"-18 UNC-2B thread size and a recess contact tip relationship 0.125 - 0.156" that is used where longer electrical stick-out is needed or when the nozzle touches the work place is made of 122 DHP copper alloy. It has a 3-piece design that includes a nozzle housing that is cut and formed from copper alloy tubing, a nozzle insert machined from a solid brass and nozzle insulator constructed of silicone material. It has nozzle insert that allows machining of internal threads in order to match the gas diffuser. Nozzle offers electrical insulation required from the gas diffuser using the nozzle insulator.