What should you not cut with a plasma cutter?
A plasma cutter is a powerful tool designed specifically for cutting electrically conductive metals. While it delivers fast, clean results on steel, stainless steel, and aluminium, several materials must never be cut with plasma due to safety risks, machine damage, and chemical hazards. Knowing what to avoid ensures safe operation and protects both the operator and the equipment.
Plasma cutting works by creating an electrically charged arc and superheating a gas stream to temperatures over 20,000°C. This arc requires the workpiece to be electrically conductive so the circuit can be completed. Materials that do not conduct electricity cannot form or sustain a plasma arc, making them unsuitable and often dangerous to cut.
Wood, plastic, foam, and composites are all non-conductive. Attempting to cut these materials results in burning, toxic fumes, and fire hazards. Plasma cutters are not designed for organic or synthetic materials, and the extreme heat will instantly ignite them.
Concrete, stone, glass, and ceramics also cannot be cut because the plasma arc cannot penetrate or maintain stability in these non-conductive, brittle materials. These substances will crack, shatter, or explode under thermal shock.
Specific coated or galvanised metals can technically be cut, but doing so without proper ventilation is dangerous. Cutting these materials releases hazardous fumes such as zinc oxide or toxic paint vapours. Adequate extraction systems and PPE are essential when cutting any coated surface.
Finally, materials containing chlorinated coatings, such as PVC-coated metal, must be strictly avoided. Plasma cutting PVC generates phosgene gas, a hazardous and potentially lethal chemical.
Non-conductive materials: Wood, plastic, rubber, foam, and composites should never be plasma cut.
Brittle materials: Concrete, glass, stone, and ceramics cannot conduct electricity and may shatter.
PVC or chlorinated coatings: Cutting these can release toxic phosgene gas.
Flammable materials: Anything combustible will ignite instantly under plasma temperatures.
Hazardous coatings: Galvanised or painted metal requires proper ventilation and safety gear.
Metal-only tool: Plasma cutters are engineered for use with conductive metals.
A plasma cutter should only be used on conductive metals. Cutting non-conductive or coated materials is unsafe and can cause fires, toxic fumes, or equipment damage.
