Abstract: A plasma arc torch for cutting metal with the heat of a constricted arc and removing the molten material with a jet of hot ionized gases comprises a nozzle assembly in the torch includes a nozzle base and an insulator with a constricting orifice. The base and insulator are spaced from each other to form a flow path for a coolant such as water. An interference fit between the base and the insulator exerts a radially outward force on the insulator to enable the base and insulator to be assembled and disassembled with a pressing or pulling force in the approximate range of 0.3 to 16.0 pounds.