Most metal parts in industrial production need permanent identification before they leave the factory. QR codes, serial numbers, data matrix codes and barcodes are the standard approach — and fiber laser is the technology used to apply them on steel, aluminum, brass and other metals.
This guide focuses on the practical side: which metals need which power level, which code format suits which application, and how to get consistent, scanner-readable marks across production batches.
Fiber Laser
Standard choice for metals. Better absorbed than CO2 at ~1070 nm wavelength.
Stainless Steel
Most consistent results. Good contrast, stable process, 20W–30W typically sufficient.
Aluminum / Brass
Bare aluminum and brass need more power headroom (30W–50W) for reliable throughput.
QR / Data Matrix
QR for general traceability; data matrix for small surfaces (3×3 mm minimum).
Quick Answer: Fiber Laser, Matched to Your Metal and Application
For most industrial metal part marking, a fiber laser marking machine is the correct starting point. The right configuration depends on three factors: the metal material, the marking content (QR code, serial number, logo), and your production throughput.
| Metal / Surface | Typical marking job | Recommended power | Primary consideration |
|---|---|---|---|
| Stainless steel (304/316/201) | Serial numbers, QR codes, logos, nameplates | 20W–30W | Surface finish affects contrast on polished SS |
| Carbon steel / mild steel | Part IDs, batch codes, structural marking | 30W–50W | Oxidation layer; verify after surface treatment |
| Aluminum — anodized | Branding, QR codes, panels | 20W–30W | Mark after anodizing for best results |
| Aluminum — bare | Part IDs, contrast marking | 30W–50W | High reflectivity; test contrast carefully |
| Brass | Logos, part numbers, fittings | 30W–50W | Reflective; sample testing required |
| Copper | Electrical component IDs | 50W+ | Very high reflectivity; verify with sample first |
| Titanium | Medical implants, aerospace fasteners | 20W–50W | Tight frequency control for color marking |
| Coated / painted metal | Serial numbers, logos, barcodes | 20W–30W | Test coating reaction and edge quality |
Not sure which power level fits your parts?
Send us your material type, surface finish, code size and output target. We can recommend a starting configuration before you invest.
What Industrial Part Marking Actually Requires
Most buyers ask "can this laser mark metal parts?" — but that question is too easy. Every fiber laser above 20W can make a visible mark on stainless steel. The harder question is whether the machine can produce scanner-readable, repeatable, production-stable marks on your specific surface and at your required speed.
The difference between a visible mark and a usable traceability mark comes down to three things:
Contrast
The mark must create enough visual separation from the background for scanners to detect it — not just visible to the human eye, but readable by 2D cameras in automated systems.
Edge sharpness
Each cell in a QR code or data matrix must have clean edges. Blurred or smeared edges increase scan error rate even if the mark looks acceptable visually.
Repeatability
A code that passes verification once must pass consistently across batches, shifts, and part variations. Parameter stability — focus, speed, power — matters as much as the initial setting.
Surface suitability
Polished, brushed, anodized and coated surfaces behave differently. Parameters optimized on one finish may not work on another. Always test on the actual production surface.
Code Types for Metal Part Identification
Industrial traceability uses several standard code formats. The right format depends on data volume, part surface area, and how the code will be read in production.
| Code type | Data capacity | Minimum size on metal | Scanner needed | Best for |
|---|---|---|---|---|
| QR Code | Up to ~4,000 characters | ~5×5 mm (standard) | 2D camera scanner | Part traceability, batch data, URLs, production records |
| Data Matrix (DMC) | Up to ~2,000 characters | ~3×3 mm (compact) | 2D camera scanner | Aerospace, medical, automotive — very small parts with limited marking area |
| 1D Barcode | Up to ~30 characters | ~15 mm wide minimum | 1D laser scanner | Warehouse management, simple part IDs, existing barcode systems |
| Serial number (text) | Limited by character height | ~1 mm character height minimum | Human-readable, OCR possible | Service records, legal compliance marking, equipment nameplates |
| Combination layout | Multiple elements | Depends on field size | Mixed | Nameplates with logo + serial + QR code in one layout |
For QR codes and data matrix on metal, minimum size guidelines assume standard industrial 2D scanners at 15–30 cm reading distance. Verify readability with your specific scanner and distance before production.
Laser Marking Results by Metal Type
Different metals absorb fiber laser energy differently. The table below summarizes typical results, challenges, and recommended starting power for the most common industrial metals.
| Metal | Typical mark type | Contrast level | Recommended power | Main challenge | Common applications |
|---|---|---|---|---|---|
| Stainless steel 304, 316, 201 |
Black marking, surface marking, deep engraving | High | 20W–30W (standard) 50W (deep engraving) |
Polished SS surfaces reduce contrast vs brushed finish | Serial numbers, QR codes, medical instruments, kitchenware, nameplates |
| Carbon steel / mild steel | Surface marking, deep engraving, white marking | Medium–high | 30W–50W | Oxidation layer affects mark depth; verify after any surface treatment | Automotive components, structural parts, batch codes, stamps |
| Aluminum — anodized 6061, 5052 |
Dark marking on anodized layer | High | 20W–30W | Mark after anodizing; marking before anodizing may be covered | Aerospace panels, electronics housings, automotive trim, brand plates |
| Aluminum — bare | Surface marking, contrast marking | Medium | 30W–50W | High reflectivity; harder to achieve consistent contrast than anodized | Industrial parts, heat sinks, fixtures, structural components |
| Brass | Surface marking, dark/white marking | Medium | 30W–50W | Reflective; parameter tuning required; sample test recommended | Fittings, valves, electrical connectors, decorative hardware |
| Copper | Surface marking | Low–medium | 50W+ | Very high reflectivity; standard fiber not always ideal — confirm by sample | Electrical components, heat exchangers, busbars |
| Titanium | Color marking, surface marking | High (varies by color) | 20W–50W | Parameter sensitivity; different colors require precise frequency control | Medical implants, aerospace fasteners, premium industrial hardware |
All values are indicative starting points. Verify on your actual part surface and finish before committing to production parameters. For detailed parameter tables, see the fiber laser marking parameters guide.
Reference Marking Parameters (20W and 30W — Real Test Data)
The parameters below are derived from GWEIKE production test data for 20W and 30W fiber laser marking machines. These are starting-point references — your actual parameters will vary based on part surface condition, focal position and required mark appearance. Always verify on test pieces.
Parameter columns: Fill spacing (mm) · Speed (mm/s) · Power (%) · Frequency (kHz)
| Material | Mark type | Fill (mm) | Speed (mm/s) | Power (%) | Freq (kHz) | Power level |
|---|---|---|---|---|---|---|
| Stainless Steel | ||||||
| Stainless steel | Black marking | 0.01 | 100 | 40 | 80 | 20W |
| Stainless steel | White marking | 0.05 (cross) | 1000 | 65 | 35 | 20W |
| Stainless steel | Deep black | 0.05 | 500 | 80 | 20 | 20W |
| Stainless steel | Brushed effect | 0.09 | 1000 | 70 | 35 | 20W |
| Stainless steel | Black marking | 0.01 | 200 | 35 | 60 | 30W |
| Stainless steel | White marking | 0.05 (cross) | 1000 | 35 | 35 | 30W |
| Stainless steel | Deep black | 0.05 | 500 | 50 | 20 | 30W |
| Aluminum | ||||||
| Die-cast aluminum | White marking | 0.05 (cross) | 100 | 95 | 45 | 20W |
| Aluminum alloy | Deep black | 0.01 (cross) | 300 | 100 | 30 | 30W |
| Brass | ||||||
| Brass | White marking | 0.05 (cross) | 1000 | 80 | 40 | 20W |
| Brass | White marking | 0.05 (cross) | 1000 | 80 | 40 | 30W |
| Brass | Deep black | 0.01 (cross) | 200 | 95 | 20 | 30W |
| Copper | ||||||
| Copper | Deep white | 0.02 | 100 | 100 | 20 | 20W |
| Copper | Deep red tint | 0.01 | 100 | 100 | 20 | 20W |
| Copper | Deep white | 0.02 | 130 | 100 | 20 | 30W |
| Iron / Mild Steel | ||||||
| Mild steel | White marking | 0.05 (cross) | 1000 | 55 | 35 | 20W |
| Mild steel | White marking | 0.05 (cross) | 1000 | 35 | 35 | 30W |
Source: GWEIKE 20W and 30W fiber laser marking test data. "Cross" fill means bidirectional cross-hatch scan. Power % is relative to rated output. Frequency in kHz. These are reference starting points; actual production parameters require verification on your specific surface and material batch.
20W vs 30W vs 50W for Industrial Metal Part Marking
Power selection for metal part marking is about matching power density to the material's absorption characteristics and your cycle time requirement — not choosing the highest number available. For a full comparison across all marking scenarios, see the 20W vs 30W vs 50W fiber laser marking machine guide.
Choose 20W when:
- Main material is stainless steel or anodized aluminum
- Production volume is low to moderate
- Marking content is text, logos or standard QR codes
- Deep engraving is not required
- Budget control is a priority
Choose 30W when:
- You mark a mix of materials (SS + aluminum + mild steel)
- Moderate to high daily volume
- Brass or aluminum parts are part of the workload
- You need a balance of cost, speed and flexibility
- 30W is the most common choice for general industrial use
Choose 50W when:
- Copper, brass or other reflective metals are a significant part of the workload
- High daily throughput requires faster cycle times
- Deep engraving on carbon steel or stainless steel is required
- Future expansion to harder materials is expected
- Productivity outweighs initial cost
Industry Applications: How Metal Part Marking Is Used
Automotive supply chain — direct part marking (DPM)
Automotive tier-1 and tier-2 suppliers apply data matrix codes directly on engine blocks, transmission housings, brackets and fasteners for traceability through the full supply chain. Data matrix is preferred because it fits on small surfaces and survives post-processing (e-coating, painting, heat treatment).
Typical setup: 30W or 50W fiber laser, data matrix code, steel or aluminum parts. Verify code readability after any surface treatment that follows marking.
Electronics and PCB — component and housing identification
Electronics manufacturers mark aluminum housings, heatsinks and connectors with serial numbers and QR codes for after-sales tracking and warranty management. Anodized aluminum produces particularly clean, high-contrast marks and is one of the easiest metal surfaces for fiber laser marking.
Typical setup: 20W or 30W fiber laser, QR code or serial number on anodized aluminum or stainless steel housing.
Industrial tools and hardware
Tool manufacturers mark logos, model numbers, serial codes and certifications on stainless steel and carbon steel tools, valves, fittings and hardware. Marks must remain legible after years of use in demanding environments. Deep engraving may be specified for parts that face abrasion or chemical exposure.
Typical setup: 30W–50W fiber laser, text and logo on stainless steel or carbon steel.
Medical instruments and implants
Medical-grade stainless steel and titanium parts require permanent, biocompatible marking for regulatory traceability (UDI — Unique Device Identification). Laser marking is the preferred method because it does not use inks or adhesives and does not compromise the part surface.
Typical setup: 20W–30W fiber laser or MOPA, data matrix code on stainless steel or titanium. Parameters require careful validation for compliance.
What to Check Before Buying a Laser Marking Machine for Metal Parts
Sample Evaluation Checklist
- Is the sample made on the same metal grade as your actual production part?
- Is the surface finish (polished / brushed / anodized / coated) the same?
- Is the code size identical to your real application?
- Are QR or data matrix codes scanner-readable at your normal scanning distance?
- Is edge quality consistent across the entire code area?
- Is cycle time realistic for your output requirement?
- Are multiple samples consistent across a batch of at least 5–10 pieces?
- Does the mark meet your permanence requirements (abrasion, chemical, temperature)?
- If the part goes through post-processing (painting, coating), has the mark been tested after treatment?
For applications with specific code format requirements (QR, data matrix, 1D barcode), also verify with your actual traceability system scanner before signing off on the parameter set.
Looking for a fiber laser marking machine for industrial part identification?
GWEIKE fiber laser marking machines are used for serial number marking, QR code traceability and direct part marking on steel, aluminum, brass and other metals. Tell us your material, code type and production volume for a starting recommendation.
FAQ — Laser Marking for Metal Parts
What is the best laser for marking metal parts?
Fiber laser is the standard choice for metal part marking. It works on stainless steel, aluminum, carbon steel, brass and titanium, and produces permanent, high-contrast marks for QR codes, serial numbers, logos and traceability codes. CO2 laser is more suitable for non-metals.
What is the difference between a QR code and a data matrix on metal parts?
Data matrix (DMC) is more compact — it can fit in a 3×3 mm area — making it common in aerospace, medical and automotive applications where part surfaces are small. QR codes hold more data and are easier to read with standard mobile camera scanners. Both can be marked on metal with fiber laser.
What is direct part marking (DPM)?
Direct part marking means the identification code is applied directly onto the part surface, rather than on a label or tag attached to the part. Laser marking is a common DPM method because the mark is permanent, clean, and survives manufacturing processes (painting, coating, heat treatment) that would destroy adhesive labels.
What power level is needed for laser marking metal parts?
For most standard industrial marking on stainless steel and anodized aluminum, 20W to 30W is sufficient. For bare aluminum, brass, carbon steel or higher throughput, 30W to 50W is more practical. Match power to your material, mark size and production speed — not the highest number available.
How small can a QR code or data matrix be on a metal part?
For reliable scanner readability, a QR code on metal should generally be at least 5×5 mm. Data matrix codes can go smaller — down to about 3×3 mm — but require a 2D camera scanner with sufficient resolution. Code readability depends on contrast and edge sharpness, not just size.
Can laser marking survive surface treatment after marking?
It depends on the process and depth of the mark. Laser marks on steel can survive e-coating, powder coating and painting if the mark depth is sufficient. On anodized aluminum, marking should be done after anodizing for best results — the anodized layer seals the mark. Always verify with test pieces before committing to production sequence.
Can one laser marking machine mark different metals?
Yes. A fiber laser marking machine can mark stainless steel, aluminum, carbon steel, brass and titanium using different parameter settings for each material. A programmable recipe system makes it easy to switch between setups in production with multiple material types.
Is fiber laser better than CO2 for metal part marking?
Yes, for metals. Fiber laser wavelength (around 1070 nm) is well absorbed by metals. CO2 laser wavelength (10,600 nm) is poorly absorbed by most metals and is more suitable for non-metal materials such as wood, acrylic and leather.
Conclusion
The best laser marking machine for metal parts is not simply the most powerful one. It is the setup that produces the right mark — QR code, data matrix, serial number or logo — on your specific metal, surface finish, and part geometry, at the speed your production requires.
Fiber laser is the standard technology for industrial metal part identification. For most stainless steel and anodized aluminum jobs, 20W to 30W is practical. For bare aluminum, brass, carbon steel and higher throughput, 30W to 50W becomes more appropriate. For copper and other highly reflective metals, 50W and careful process validation are usually necessary.
Before purchasing, always test on your actual production surface and verify scanner readability — not on a substitute material or a single sample under ideal conditions.
For more detail on specific metals, see the stainless steel laser marking guide or the aluminum laser marking guide. For power selection, see the 20W vs 30W vs 50W comparison guide.
