Cutting
Plasma Cutting vs Oxy-Fuel Cutting
Plasma cutting forces an ionized gas arc through a constricted nozzle to melt and eject any conductive metal. Oxy-fuel preheats carbon steel to ignition temperature and burns it with a pure oxygen jet. The core trade is plasma speed and material range against oxy-fuel thick-section capacity and rock-bottom equipment cost.
| Plasma Cutting | Oxy-Fuel Cutting | |
|---|---|---|
| Material range | Any conductive metal: steel, stainless, aluminum, copper | Carbon steel only; no stainless or aluminum |
| Practical thickness | 0.5 to 38 mm quality cuts, 50 mm sever | 6 to 300 mm, best above 25 mm |
| Cut speed, 12 mm mild steel | 1,400 to 1,800 mm/min | 400 to 500 mm/min |
| Edge quality | 2 to 4 degree bevel, kerf 2 to 4 mm | Square edge, kerf 1.5 to 2.5 mm, wider HAZ |
| Equipment cost | $2,500 to $6,000 handheld; $60,000+ CNC table | $400 to $800 torch set; $3,000 track burner |
| Power and gas inputs | 240 V or 3-phase power plus clean dry air | Oxygen and acetylene or propane, no electricity |
| Consumables | Nozzle and electrode set $5 to $10, 2 to 4 hr life | Cutting tips $10 to $20, weeks of life |
Choose Plasma Cutting when
- You cut stainless, aluminum, or mixed nonferrous work
- Production cutting of plate under 25 mm where speed pays
- CNC nesting jobs that need tight kerf and a small HAZ
Choose Oxy-Fuel Cutting when
- Carbon steel sections above 50 mm thick
- Field and remote work with no electrical power
- Startup tooling budget under $1,000
The verdict
Buy plasma if you cut mixed metals or run production under 25 mm; the speed advantage is 3x to 4x and it handles stainless and aluminum. Keep oxy-fuel for carbon steel over 50 mm and remote field work. Most fab shops end up owning both for under $10,000 combined.
Cost comparison
A handheld plasma rig runs $2,500 to $6,000 plus roughly $4 to $8 per arc-hour in consumables and power. An oxy-fuel outfit costs $400 to $800 with $8 to $15 per hour in oxygen and fuel gas. On 12 mm plate, plasma cuts 3x to 4x faster, so labor drives cost per foot below oxy-fuel despite pricier consumables. The crossover sits near 25 to 40 mm; above that, oxy-fuel wins on both speed and consumable burn.
Common questions
Can plasma cut steel thicker than 50 mm?
High-amperage industrial systems in the 400 to 800 A class will sever 75 to 160 mm, but edge quality drops and consumable cost climbs fast. Past 50 mm, oxy-fuel gives a squarer edge at a fraction of the operating cost.
Why can't oxy-fuel cut stainless or aluminum?
The process depends on iron oxidizing exothermically in the oxygen stream. Chromium oxide and aluminum oxide films block that reaction, so the cut will not propagate no matter how much preheat you apply.