Laser Cutter vs. Plasma Cutter: Which One Cuts the Metal You Have?
Summary
A plasma cutter is the cheaper tool for steel plate: a handheld inverter unit and an air compressor will sever metal up to about an inch thick, and clean-cut roughly half that. A laser cuts by melting a spot often under half a millimetre wide, so its edge is finer and it can also cut non-metals, but on a desktop budget it only gets through sheet up to about a millimetre. Handheld fiber lasers close some of the gap, at several times the price of a plasma unit.
Two ways of melting a line through metal
Hypertherm, which makes plasma cutting systems, describes plasma as a gas that has been heated until it becomes electrically conductive. A plasma cutter forces a gas such as nitrogen, oxygen, argon or plain air through a narrow nozzle, an electric current turns that gas flow into a plasma arc, and the arc cuts the workpiece by melting it and blowing the molten metal away. Handheld systems pair an inverter power supply, like a welder's, with compressed air from a compressor or bottle.
A laser cutter has no arc. TRUMPF, which builds industrial laser systems, calls laser cutting a contact-free slitting process: the beam is concentrated on a point with a diameter that is often less than half a millimetre, the material melts or vaporises, and a cutting gas emitted from the same nozzle blows the melt out of the kerf. Mild steel is flame cut with oxygen at up to 6 bar; stainless steel is fusion cut with nitrogen or argon at 2 to 20 bar.
What each one will cut
Because plasma relies on an electric arc, it only works on conductive material. Hypertherm lists mild steel, carbon steel, stainless steel, aluminum, copper and brass. Arccaptain's Q&A for its CUT55 Prolux says the same from the other side: it cuts any electrically conductive metal and cannot cut wood, plastic or stone.
The laser has no such limit. TRUMPF's list runs from steel, aluminium and stainless to plastics, glass, wood and ceramics. That is why the desktop machines on this site are sold as engravers and cutters for wood and acrylic first, with metal as the exception.
Thickness is where plasma pulls ahead
Arccaptain's handheld plasma cutters, which are consumer and small-shop units, quote two figures per machine: an ideal clean-cut thickness and a maximum severance thickness, the latter being how thick a piece can be parted at all. On 220 to 240 V power the CUT50 is rated for a 3/8" clean cut and 11/16" severance, the CUT55 Prolux for 9/16" (14 mm) and 7/8" (22 mm), and the CUT65MP for 3/4" (20 mm) and 1-1/4" (32 mm). Run on a 110 to 120 V outlet the ratings fall: the CUT50 to a 1/4" clean cut and 3/8" severance, the CUT65MP to a 3/8" clean cut and 1/2" severance.
Industrial sheet-metal lasers cover 0.5 mm to more than 30 mm, according to TRUMPF, so at the top of the market the laser matches plasma on thickness. That capacity does not reach the desktop. xTool's F1 Ultra Q&A gives cutting examples of 0.3 mm stainless steel and 0.4 mm brass, and its example for 0.2 mm aluminum runs 10,000 passes over the same line. The LaserPecker LP5 is rated to cut brass, stainless, aluminum and titanium up to 1 mm.
Handheld fiber laser welders sit in between. Arccaptain's LW1200 is a 1,200 W fiber unit sold for welding, cutting and cleaning; its published welding range is 0.3 to 4 mm and the cutting mode is described as for thin metal, without a thickness rating.
Edge, heat and what happens next
TRUMPF's account of fusion cutting is that the nitrogen or argon does not react with the metal in the kerf, so the edge comes out almost free of oxide and burrs and needs little rework. A plasma arc, by Hypertherm's figures, runs at temperatures approaching 40,000°F and parts the metal by blowing melt out of the cut, which is why Arccaptain sells gouging and rust-removal modes on the same machines: the arc is a heat tool first and a cutting tool second.
Setup and running costs
A plasma cutter needs air. Arccaptain's Q&A for the CUT50 asks for a compressor delivering at least 90 PSI and 5 CFM, and the CUT55 Prolux for a minimum of 60 PSI with 4 to 5 CFM of clean, dry air. Both are dual-voltage; the Prolux ships with a 240-to-120 V adapter and runs on a standard 20-amp circuit at 110 V. The torch consumables (electrodes, nozzles, cups) wear and are sold as kits.
A laser needs the eyewear its maker specifies (the LW1200 ships with laser safety glasses), an enclosure or exhaust for the fumes, and, for the fiber welders, a 220 V supply; the LW1200 is air-cooled and needs no external chiller. Our safety guide covers what the laser class on the label tells you.
Which one to buy
| If you mainly want to | The tool that fits | Why |
|---|---|---|
| Cut steel plate, angle, tube or rusty stock by hand | Plasma cutter | Rated to 3/4" clean cut on the largest handheld unit; starts on painted or rusted surfaces |
| Cut shapes from wood, acrylic, leather, paper | Diode or CO2 laser | Plasma cannot cut non-conductive material at all |
| Cut and engrave thin metal parts, tags, jewelry | Fiber laser engraver | Sub-millimetre spot and a fine edge; sheet up to about 1 mm |
| Feed a CNC table for repeat parts | CNC-ready plasma (or an industrial laser) | Arccaptain's CUT65MP ships with a CNC interface for PlasmaCam, Torchmate, Langmuir, Mach3 and LinuxCNC |
| Weld thin sheet as well as cut it | Handheld fiber laser welder | One 1,200 W unit welds 0.3 to 4 mm and cuts thin metal, at a price several times a plasma cutter's |
Sources
- Hypertherm — Plasma cutter technology
- TRUMPF — Laser cutting
- TRUMPF — Fusion cutting
- Arccaptain — CUT55 Prolux Non-Touch Plasma Cutter
- Arccaptain — CUT50 HF Start Portable Plasma Cutter
- Arccaptain — CUT65MP NON-HF CNC Plasma Cutter
- Arccaptain — LW1200 1200W Handheld Laser Welder
- xTool Support — xTool F1 Ultra Q&A
- LaserPecker — LP5 Smart 20W Fiber + Diode Laser Engraver
Specs and prices are as published on these pages on the date above and can change; check the manufacturer or retailer before you buy.