Mild Steel vs Stainless Steel for Laser Cutting

Overview

Mild steel and stainless steel are the two most commonly laser-cut materials. They look similar as raw sheet, but they behave very differently during cutting, in service, and in cost. Choosing the right one comes down to your application — and understanding the trade-offs.

Mild Steel

Mild steel (also called carbon steel or CRS/HRS) is the workhorse of fabrication. It's cheap, easy to cut, easy to weld, and available in a wide range of thicknesses.

Common Grades

• Grade 250 (AS/NZS 3678) — General structural and fabrication use
• Grade 350 — Higher strength structural applications

Properties

Laser Cutting Characteristics

• Cuts quickly and cleanly with an oxygen assist gas
• Thicker materials cut well — up to 20-25mm on a fibre laser
• Cut edge has a thin oxide layer (dark finish) when cut with oxygen
• Nitrogen cutting produces a clean, oxide-free edge but is slower and uses more gas

Best For

• Structural brackets and frames
• Enclosures and housings (when painted or powder-coated)
• Machinery parts
• Any application where the part will be coated or isn't exposed to moisture

Stainless Steel

Stainless steel is an alloy containing chromium (at least 10.5%), which forms a passive oxide layer that resists corrosion. It's stronger, harder, and more expensive than mild steel.

Common Grades

• 304 (2B finish) — The most common grade. Good all-round corrosion resistance. Used in food, medical, architectural, and general fabrication. See our 304 vs 316 comparison for a deeper dive.
• 316 (marine grade) — Higher corrosion resistance due to molybdenum content. Used in marine, chemical, and high-corrosion environments.

Properties

Laser Cutting Characteristics

• Cut with nitrogen assist gas for a clean, bright edge
• Slower cutting speeds than mild steel at the same thickness
• Maximum thickness is generally lower — around 12-16mm on a fibre laser
• Produces a high-quality edge that usually doesn't need deburring
• More reflective than mild steel — modern fibre lasers handle this well

Best For

• Food and beverage equipment
• Marine and outdoor applications
• Medical and pharmaceutical
• Architectural features
• Any application requiring corrosion resistance without painting

Head-to-Head Comparison

Cost Comparison

The price difference is significant. As a rough guide for Australian pricing:

• Mild steel sheet: ~$3–6/kg depending on thickness and quantity
• 304 stainless sheet: ~$10–18/kg
• 316 stainless sheet: ~$15–25/kg

On top of material cost, stainless takes longer to cut (higher laser time = higher cutting cost) and uses more nitrogen gas.

Example: A 300x200mm bracket in 3mm material:

• Mild steel: ~$15–25 (laser cut, deburred)
• 304 stainless: ~$35–55 (laser cut, deburred)

When to Use Which

Choose Mild Steel When:

• The part will be painted, powder-coated, or zinc-plated
• It's an internal structural component not exposed to moisture
• Cost is a primary concern
• You need thick material (>12mm)
• The part will be heavily welded

Choose Stainless Steel When:

• The part is exposed to water, chemicals, or outdoor weather
• It's used in food, medical, or marine environments
• You want a clean, unpainted finish
• Corrosion resistance is non-negotiable
• The part needs to be cleaned/sterilised regularly

Consider Aluminium When:

• You need light weight
• Corrosion resistance matters but stainless is overkill
• The part is cosmetic (anodising gives excellent finishes)
• You're working in aerospace or automotive weight-sensitive applications

Get a Quote

Not sure which material is right for your project? Compare properties side by side with our Material Comparison Tool, or use the Material Weight Calculator to estimate part weight and material cost.

Upload your CAD file to our instant sheet metal quoting tool and compare prices across materials and thicknesses in seconds. Or contact us for advice. For design tips that will save you money, check out our sheet metal DFM guide and Laser Cutting Design Guide. Use our Sheet Metal Cost Estimator for a quick price without uploading a file.