Oxyfuel cutting is typically used to cut structural steel.

• A. Aluminum
• B. Stainless steel
• C. Structural steel
• D. Non-ferrous metal

Answer: (C)

Oxyfuel cutting relies on an exothermic reaction between iron in the metal and a jet of pure oxygen, which heats and oxidizes the metal to the point it can be cut through. This process works best on carbon steels, where enough carbon allows the metal to sustain rapid oxidation and form slag that can be blown away, making thick structural sections economical and practical to cut.

Structural steel is a carbon steel commonly used in construction, so it responds well to oxyfuel cutting: the heat from combustion drives the cut, and the oxide/slag can be separated cleanly. Other metals don’t fit this pattern. Aluminum and other non-ferrous metals form protective oxide layers that resist further oxidation, making oxyfuel cutting inefficient or ineffective. Stainless steel contains chromium, which forms a hard protective oxide and also resists the oxidizing reaction required for straightforward oxyfuel cutting. So, oxyfuel cutting is typically used for structural steel, not aluminum, stainless steel, or other non-ferrous metals.