What psi should the oxygen regulator be for an exothermic cutting torch?

• A. 60-70 psi
• B. 120-130 psi
• C. 150-160 psi
• D. 90-100 psi

Answer: (D)

Oxygen pressure for an exothermic cutting torch must be high enough to drive a strong, steady oxidation at the cut line. The typical working range is 90–100 psi. This level provides a robust cutting oxygen flow to keep the heat concentrated at the preheated steel and to blow away the molten oxide for a clean cut. If the pressure is too low, the cut will be slow or fail to start; if it’s too high, the jet can become overly aggressive, increasing the risk of unintended heating, equipment strain, or safety hazards in a collapse environment. This 90–100 psi range is what training and practice guidelines usually align with for exothermic cutting.