We specialize in fiber laser cutting of 20mm medium-thick SUS400 series ferritic stainless steel sheets, delivering precision-cut blanks and structural components for applications where magnetic response, thermal efficiency, and cost control are priorities. The SUS400 family—including grades such as SUS430, SUS410S, SUS409L, and SUS420J2—is a ferritic chromium stainless steel series characterized by high thermal conductivity, low thermal expansion, and strong ferromagnetism.
At the 20mm thickness range, SUS400 plate sits at the intersection of sheet and plate processing: thick enough to require high-power laser systems and specialized parameter control, yet thin enough to achieve clean, dross-free edges with proper nitrogen assist and speed modulation. Our production line is calibrated specifically for this medium-thick ferritic range, ensuring cut edges remain free of excessive oxide and retain the material's inherent corrosion resistance.
0.3mm – 0.5mm (depending on beam focus and gas pressure)
Surface Finish
No.1 (Hot Rolled) / 2B / No.4 / Pickled
Edge Condition
Dross-free / Minimal slag / Ready for welding or machining
SUS400 Grade Chemical Composition and Technical Property is as below：
Standard
C % max
Si max
Mn max
P max
S max
tensile strength（MPa）
yield strength（MPa）
Elongation%
SUS400
0.2
1
1
0.04
0.03
400-510
≥205
≥17
SUS400 Series Material Characteristics
Magnetic Response: Unlike austenitic 304 or 316, all SUS400 grades are strongly ferromagnetic. This is advantageous for magnetic clamping during downstream machining, separation in recycling systems, and electromagnetic shielding applications—but must be considered if the part will interface with sensitive electronic or medical equipment.
High Thermal Conductivity: Approximately 60% higher than SUS304. This means heat dissipates rapidly during laser cutting, requiring higher power density and slower traverse speeds to maintain cut penetration through 20mm thickness without losing beam focus.
Low Thermal Expansion: Roughly 30% lower expansion coefficient than austenitic grades. This reduces thermal distortion and warp tendency during cutting, making SUS400 20mm plate easier to hold flat compared to equivalent-thickness 304 or 316.
Cost Efficiency: With no nickel content, SUS400 raw material costs are typically 20–40% lower than SUS304, making it an economical choice for non-aggressive indoor or mildly corrosive environments.
20mm Medium-Thick Laser Cutting Process
Cutting 20mm ferritic stainless steel presents distinct challenges that our systems are specifically configured to manage:
High-Power Beam Delivery: 12kW–20kW fiber lasers with collimated beam delivery ensure consistent melt-pool penetration through the full 20mm section without taper-induced bottom-edge rounding.
Nitrogen Assist Optimization: High-purity nitrogen at elevated pressure sweeps molten material from the kerf, preventing chromium oxide formation that would otherwise require post-cut grinding. The result is a silver, weld-ready edge.
Minimal Heat-Affected Zone (HAZ): Despite the thickness, rapid beam traverse and efficient heat conduction into the surrounding plate keep the HAZ narrow, preserving the ferritic grain structure without sensitization risk.
Dross Control: Ferritic grades at 20mm can produce adherent dross if gas pressure is insufficient. Our parameters employ pulsed gas modulation and controlled focal positioning to eject molten slag cleanly from the bottom edge.
Typical Applications
Commercial Kitchen Equipment: Heavy-duty griddle bases, oven liner plates, and exhaust hood structural panels where magnetic mounting accessories are used.
Automotive Exhaust & Trim: Catalytic converter heat shields, muffler baffles, and decorative trim backing plates requiring magnetic attachment during assembly.
Appliance Manufacturing: Washing machine drums, refrigerator inner panels, and microwave oven chassis components in 20mm structural reinforcement gauges.
Architectural Metalwork: Decorative screens, elevator interior panels, and signage backing frames where a lower-cost stainless alternative to 304 is acceptable.
Industrial Machinery: Magnetic separator housings, conveyor guide rails, and equipment bases exposed to dry indoor atmospheres.
Energy Equipment: Transformer tank stiffeners and electrical enclosure frames leveraging the non-galling and magnetic properties of ferritic stainless.
