Plasma Cutting: The Core Process for Efficient Blanking of Medium-to-Thick Plates

Plasma cutting remains the workhorse for blanking medium-to-thick steel plates, where its combination of speed and cost-efficiency is difficult to match. The process operates by forcing a high-temperature plasma arc (10,000–25,000°C) through a constricted nozzle, melting the workpiece while a high-velocity gas jet expels the molten material to form the kerf.
 
Experimental data reveals a clear thickness-dependent performance advantage.** For mild steel, plasma cutting speed follows an inverse relationship with plate thickness, approximately S = 40/T (S in inches/min, T in inches). In practical terms, this translates to roughly 5,000 mm/min at 3 mm, 2,000 mm/min at 10 mm, and 800 mm/min at 25 mm. The economically dominant segment is 15–50 mm, which captured 40.75% of the plasma cutting machine market in 2026.
 
Comparative analysis against fiber laser clarifies plasma’s niche. Up to 12 mm, fiber laser cuts up to five times faster than plasma. However, at 16 mm the advantage disappears for a 15 kW laser, and plasma achieves faster cutting. Plasma continues to outperform a 20 kW laser at 20 mm and a 30 kW laser at 30 mm. Cost per meter confirms this crossover: laser holds an economic advantage up to 10–20 mm, beyond which plasma becomes more favourable despite higher maintenance costs. Plasma also cuts rusted, painted, or scaled plate without pre-cleaning, a significant operational advantage in structural fabrication.
 
The process is not without limitations. Kerf taper and edge roughness require parameter control, and accuracy typically ranges from ±0.3 to ±0.5 mm. Yet for large-format structural parts destined for welding and grinding, these tolerances are acceptable. With the global plasma cutting machine market projected to grow from $699.5 million in 2025 to $975.3 million by 2034, the technology continues to hold its ground as the practical choice for efficient thick-plate blanking.