Plasma Cutting

Plasma cutting uses an ionized gas arc to cut conductive sheet and plate quickly, ideal for 2D profiles in medium-tolerance metal parts, especially thicker sections.

Overview

Plasma cutting, or plasma torch cutting, uses a high-velocity ionized gas arc to cut conductive metals in sheet and plate form. The process excels at producing 2D profiles, brackets, gussets, and base plates from mild steel, stainless, and aluminum. Shops commonly use CNC plasma tables to handle anything from thin sheet up to thick plate, with good edge quality and relatively fast cycle times.

You should consider plasma cutting when you need economical profile cutting in low to medium volumes, and your part can tolerate moderate edge taper, a heat-affected zone, and looser tolerances than high-end laser or waterjet. Plasma is especially strong on thicker materials where it maintains good speed and cost-effectiveness. Tradeoffs include a rougher edge, dross that may require cleanup, limited small-hole quality, and typical tolerances in the ±0.010" to ±0.030" range depending on thickness and setup. It’s a practical choice for structural, industrial, and fabrication work where robustness matters more than cosmetic perfection or ultra-tight precision.

Common Materials

  • Mild steel A36
  • Carbon steel plate
  • Stainless steel 304
  • Stainless steel 316
  • Aluminum 5052
  • Aluminum 6061

Tolerances

±0.010" to ±0.030"

Applications

  • Structural brackets and gussets
  • Base plates and mounting plates
  • Machine guards and panels
  • Agricultural and construction equipment parts
  • Truck and trailer components
  • Industrial duct and chute sections

When to Choose Plasma Cutting

Choose plasma cutting for 2D metal parts where speed and cost matter more than fine detail or very tight tolerances. It’s well-suited to thicker plate, structural parts, and low to medium production volumes. Ideal when a heat-affected edge is acceptable and you can handle some secondary deburring or edge cleanup.

vs Laser Cutting (CO2)

Select plasma cutting over CO2 laser when cutting thicker plate (e.g., >3/8–1/2") where laser slows down or becomes costly. Plasma is more forgiving on dirty or rusty plate and offers lower equipment and part cost when ultra-clean edges, small features, and tight tolerances are not critical.

vs Laser Cutting (Fiber)

Pick plasma cutting instead of fiber laser when you need economical cutting of medium-to-heavy plate and don’t need very fine kerf width or cosmetic edges. Plasma handles mill-scale, coatings, and less-than-perfect material surfaces better, and can be more cost-effective for large, robust parts where a little taper and HAZ are acceptable.

vs Waterjet Cutting

Use plasma cutting instead of waterjet when you prioritize speed and lower cost over edge quality and absence of HAZ. For thick steel structural parts, base plates, and general fabrication work, plasma usually delivers faster throughput and cheaper parts, as long as you can tolerate some dross and moderate tolerances.

vs Shearing

Choose plasma cutting over shearing when you need complex 2D profiles, internal cutouts, or non-straight edges that a shear cannot produce. Plasma also avoids the distortion and limitations of long straight-line cuts only, making it better for nested shapes and parts with multiple internal features.

Design Considerations

  • Keep hole diameters at least equal to material thickness (preferably 1.5–2x) to avoid tapered, out-of-round holes
  • Avoid specifying critical tolerances on plasma-cut edges; reserve tight dimensions for secondary machined features if needed
  • Group similar material thicknesses and alloys to simplify setup and reduce cost per part
  • Allow for a small kerf width and edge taper in your flat pattern; don’t stack dimensions assuming perfectly square cuts
  • Provide clear DXF/DWG flat patterns with layer conventions for cut, etch, and non-cut features to speed quoting and programming
  • Keep very fine details, thin webs, and sharp internal corners to a minimum, as they slow cutting and may not hold up thermally