Plasma Sheet Cutting

Plasma sheet cutting uses a superheated ionised gas jet to cut electrically conductive sheet material.

Plasma Sheet Cutting uses a high-velocity plasma arc to cut sheet metal. It is typically faster than laser cutting for thicker materials but produces a rougher cut edge.

Plasma Sheet Cutting is an automatic workstep — it runs automatically after the Sheet node is created during import. WSi creates the Plasma Sheet Cutting node as part of the import workflow.

When to use this process

Plasma Sheet Cutting is available automatically when:

• You import a DXF or GEO file as a sheet metal part
• The material is too thick for effective laser cutting (generally above 6 mm for mild steel)
• A rougher cut edge is acceptable for the application

See also: Waterjet Sheet Cutting and Laser Sheet Cutting.

Editing Plasma Sheet Cutting Parameters

To change the nesting mode after the node is created, right-click the Plasma Sheet Cutting node in the Graph View and select Edit Nesting Mode.

Result

After Plasma Sheet Cutting runs:

• A Sheet Cutting node appears in the Graph View, connected from the Sheet node
• The Tree View shows the cutting parameters and results (contour count, scrap, utilisation)
• Cut geometry is available as output for the next process (typically Bending)

WARNING

Plasma cutting produces a wider heat-affected zone than laser cutting. For parts with critical dimensional tolerances on cut edges, verify the tolerance chain in the Details panel before proceeding to bending.

Parameters

The parameters for this process are configured in the database — see the Sheet cutting page.

Technical Background

Plasma cutting works by constricting an electric arc through a narrow nozzle, forcing ionized gas — typically compressed air, nitrogen, or a mixture of argon and hydrogen — into a superheated, electrically conductive stream called plasma. The arc temperature reaches approximately 20,000°C, which melts any electrically conductive metal virtually instantaneously.

A high-velocity gas jet surrounding the plasma core blows the molten material away from the cut, forming the kerf. Unlike laser cutting, the plasma arc physically extends from the torch tip to the workpiece — there is no optical lens to align and no focused beam that can lose energy over distance. This makes plasma systems mechanically simpler but limits their precision compared to laser.

Plasma cutting works on any electrically conductive material — mild steel, stainless steel, aluminium, copper, and their alloys. Unlike oxygen-assisted laser cutting, which benefits from the exothermic reaction on mild steel, plasma cutting uses the same physical mechanism regardless of material. This means plasma is consistently slower on mild steel than oxygen laser, but it does not require different process parameters when switching between material types.

The cut edge produced by plasma is rougher and the heat-affected zone is wider than laser cutting, which is why plasma is typically reserved for thicker materials where the trade-off in edge quality is acceptable. Cutting speed decreases as material thickness increases, since more energy is required to melt through the additional material.