Plasma cutting

How thick can a plasma cutter cut?

Quick answer

A 40 A unit cleanly cuts 10 mm steel (severs 14 mm); 60 A handles 16 mm clean; 80–100 A machines reach 28 mm+.

· · Technical guidance compiled from trade practice and manufacturer data; our source-verification program is in progress — see our editorial policy.

Numbers by machine/output class

OutputClean cut (steel)Severance
40 A~10 mm14 mm
60 A~16 mm22 mm
80 A~22 mm30 mm
100 A+~28 mm+38 mm+

Beyond single-pass

Thickness limits assume full-penetation single-pass welds. Bevelling the joint, multi-pass stacking and preheat on thick sections extend any process dramatically — that's how structural welders join 50 mm plate with the same physics. Match the machine class to the thickness you actually weld 90% of the time.