1. Stainless Steel Types and Their Marking Characteristics

304 Stainless Steel

The most common stainless steel grade. Contains ~18% chromium and ~8% nickel.

Marking behavior:

• Anneals to a deep black/dark brown consistently
• Good contrast for both annealing and engraving
• Slightly easier to mark than 316 due to lower molybdenum content
• Surface finish significantly affects results: mirror finishes produce sharper marks, brushed surfaces scatter the beam slightly

316 Stainless Steel

The “marine grade” with ~16% chromium, ~10% nickel, and ~2% molybdenum.

Marking behavior:

• Anneals to a slightly lighter black compared to 304 (molybdenum changes oxide formation)
• Requires marginally more energy for equivalent mark darkness
• More corrosion-resistant post-marking (critical for medical and marine applications)
• Passivation behavior differs — marks must be tested after your specific passivation process

17-4 PH Stainless Steel

Precipitation-hardened grade used in aerospace and high-strength applications.

Marking behavior:

• Anneals well with standard parameters
• Harder surface requires slightly more power for engraving
• Heat input can affect localized hardness — avoid excessive energy in critical areas

Other Grades (410, 420, 430)

Ferritic and martensitic grades.

Marking behavior:

• Generally mark more easily than austenitic grades (304/316) due to higher carbon content
• May produce slightly different oxide colors during annealing
• Less corrosion-resistant overall; marks must not further compromise surface integrity