Standard D/F Machine Specialties torches equipped with 1 water/out & power cable are rated at 650 amps continuous duty cycles. These ratings are, however, dictated by the contact tip. Copper starts to breakdown at 250° F. When this happens it starts to lose its properties and will begin to break down and soften. At D/F we have 2 different lines of contact tips for the different kinds and sizes of wires. Because each different size and kind of wire requires different amperages we can provide a customer with the right kind of tip for the job. D/F recommends it line of inexpensive slip-in tips (NCM) up to 450 amps and up to 1/16” wires and its line of heavy duty Cu Cr Zr threaded tips (HTM) for anything above the 450 amp range or 1/16” wire.