Text milling is a permanent marking method that creates deep physical cavities on part surfaces through CNC precision milling.
Compared to laser marking, Text Milling offers superior reliability in aerospace and medical devices by resisting sandblasting, heavy coatings, plating, and long-term wear, ensuring lifetime traceability of serial numbers, lot numbers, and UDIs.
Typical depths of 0.2-0.4mm achieve clear, durable identification, whereas laser markings are often obscured by subsequent surface treatments or fade over time.
What Is Text Milling and Why Is It Essential for Heavy-Duty Parts?
Unlike surface laser etching, Text Milling creates physical cavities through mechanical material removal. This deep marking withstands sandblasting, thick coatings, chemical etching, and decades of wear on high-value industrial parts, serving as the gold standard for aerospace (AS478 standard) and medical (FDA UDI requirements) applications.
Below is a comparison of the actual effects of laser marking versus text milling (after coating):
Left: Laser markings are often obscured by coatings. Right: Text milling remains clearly visible even in deep cavities.
Optimize with the Right CNC Text Engraving Tools
The key to success lies in spindle concentricity (runout < 0.01mm).
We recommend using 60° or 90° V-shaped carbide tools, which balance tip strength and detail resolution.
For hard materials (such as stainless steel and titanium alloys), select AlTiN-coated tools to withstand high temperatures.
Common V-shaped Cutting Tools Comparison:
Left: 60° V-cutting blade (for finer details), Right: 90° V-cutting blade (for stronger, deeper markings).
Using Single Line Fonts for CNC to Slash Cycle Time
Single Line / Stick Fonts enable cutting tools to follow a single path instead of contour grooving, reducing machining time by 50-60%. This makes them particularly suitable for high-volume production. They also minimize heat buildup in small characters, preventing melting of plastics like POM and acrylic.
Single-line Font vs. Outline Font Path Comparison:
Left: Single-path efficient continuous machining; Right: Contour requires multiple grooving passes.
Natively supported by mainstream CAM software (e.g., Fusion 360, Mastercam), or download dedicated .SHX/.Stick fonts.
Mastery of Stainless Steel Text Milling (304/316 Grades)
Stainless steel tends to harden workpieces, requiring a high-torque, low-speed strategy. Oil mist cooling is recommended; a cutting depth of 0.2mm ensures visibility and tool life. When encountering burrs, reduce feed per tooth and ensure the tool remains sharp.
Recommended Parameter Table (Stainless Steel Text Milling):
| Parameter | Recommended Value | Description |
|---|---|---|
| Depth of Cut | 0.2–0.4 mm | Optimal balance between visual quality and structural integrity |
| Spindle Speed (RPM) | 8000–12000 | Helps prevent work hardening |
| Feed per Tooth | 0.05–0.1 mm | Controls heat generation and burr formation |
| Cooling Method | Oil mist cooling (MQL) | Reduces friction and extends tool life |
| Entry Method | 1° Ramp-in | Prevents tool shock from direct plunging |
Achieving Consistent Precision Engraving Depth
For curved or uneven parts, use a 3D surface probe or spring-loaded tool holder to maintain consistent depth. A 1° ramp-in approach is recommended to avoid excessive entry caused by vertical plunging, ensuring uniformity from the first to the last character.
Optimal industrial depth: 0.2–0.4 mm (universal for aluminum/steel parts), providing clarity without compromising structural integrity.
Common FAQ
1.How does Text Milling compare to laser marking in terms of cost?
While the cycle time per part is slightly longer, Text Milling eliminates the need for costly laser maintenance. Additionally, deep cavity markings remain unaffected by coatings or plating, reducing the risk of secondary rework. Long-term, Text Milling proves more economical for high-value components.
2.How can tool breakage be prevented during stainless steel Text Milling?
Primary causes: Spindle runout or excessive feed rates. Use high-precision ER chucks + ramped feed (Ramp) instead of vertical plunging. Maintain runout within 0.005mm.
3.Are single-line fonts for CNC universally compatible across all software?
Mainstream software like Fusion 360 and Mastercam natively support them. If not available, download specialized .SHX or Stick fonts for optimized toolpaths.
4.What precision engraving depth achieves optimal visual results?
For most industrial aluminum/steel parts, 0.2-0.4mm is the ideal range. Shallow depths may blur text, while excessive depth compromises structural integrity.
Text milling remains the most reliable method for achieving high-performance, traceable results with lifetime durability. Through tool rigidity and path optimization, it ensures parts meet the highest industrial standards.
Should you have any needs, please feel free to contact us anytime!
