Laser, plasma or waterjet cutting?

TL;DR

• Laser: fine, fast cuts in thin and medium sheet.
• Plasma: quick, economical cuts in thicker steel plate.
• Waterjet: no heat, and it cuts almost any material.

Laser cutting

A focused beam melts a narrow line through the sheet. The cut is fine and the edge clean, so small holes and detailed shapes come out well.

It is at its best in thin and medium sheet. Cutting slows as the metal gets thicker.

Plasma cutting

An electric arc turns gas into plasma that melts through the metal. It works only on metals that conduct electricity, and it cuts thick plate quickly and at low cost.

The cut is wider and the edge rougher, and more heat goes into the part.

Waterjet cutting

A fine stream of water at very high pressure, usually carrying abrasive grit, wears through the material. No heat goes into the part, so the metal at the edge stays as it was.

It cuts metal, stone, glass and composites, in thick sections too. It is the slowest of the three.

No cutting method is the best one. The part decides.

How to choose

Four questions settle most cases.

• Thickness: thin sheet favours laser; thick plate favours plasma or waterjet.
• Material: plasma needs a metal that conducts; waterjet cuts almost anything.
• Edge: laser and waterjet leave a cleaner edge than plasma.
• Heat: where heat must not change the metal, choose waterjet.