DFM Guide · CNC Engraving

Logos. Text.
Serial numbers.
Engrave it right.

CNC engraving creates permanent marks via tool depth — logos, text, serial numbers, decorative patterns. Different from laser marking (no depth). Specific design rules for legibility and cost.

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01 · Engraving basics

Mechanical engraving fundamentals.

Tool tip

Vee tool typical

60° or 90° vee engraving tools standard. Diameter at depth determined by depth × tan(half angle).

Depth

0.1-0.5 mm typical

Standard engraving depth 0.1-0.5 mm. Deeper visible at distance, shallow for precision.

Width

Width = 2 × depth × tan(angle)

60° vee tool 0.3 mm depth produces ~0.35 mm wide line. 90° tool 0.3 mm depth produces ~0.6 mm wide.

Font selection

Stroke fonts

Use stroke (outline) fonts not solid fonts. Engraving traces lines; cannot fill solid shapes efficiently.

02 · Font and text

Text design rules.

Single-line stroke fonts: traced as path, fastest engraving. Standard for serial numbers, identification. Fonts: Engraver, Stroke, OEM technical fonts.

Outline fonts: letter outlines traced only. Faster than solid fill but lacks legibility at small sizes.

Solid fill fonts: letter interior pocketed out. Most legible at small sizes but slowest to engrave (5-10× longer than stroke).

Minimum readable size: 1.5-2 mm character height for most viewing. 1 mm minimum technically achievable but hard to read.

Font choice: stick to engineering fonts (Arial, OCR, technical). Avoid serif and decorative — strokes too thin for clean engraving.

03 · Logo engraving

Custom logos and graphics.

Vector required

Adobe Illustrator

Logos must be vector format (SVG, AI, DXF). Bitmap raster images cannot be cleanly engraved.

Line weight

Adjusted for tool

Logo line weight may need adjustment for chosen tool diameter. We can review and adjust.

Detail limit

Tool tip = min feature

Smallest detail = tool tip diameter. 0.1 mm tip = 0.1 mm minimum line. Larger tools faster.

Color fill optional

Paint after engraving

Engraving color: paint or epoxy filled into engraved depth, wiped flush. Black common, color per brand.

Multi-tool logos

Different depths

Complex logos may need multiple tool passes for varying line weights. Adds setup but enables fidelity.

Position accuracy

±0.05 mm typical

Logo placement on part: ±0.05 mm typical CNC accuracy. Specify position datum on drawing.

04 · Engrave vs laser mark

Choose right marking method.

CNC engraving wins when

• Tactile mark needed (Braille, ID plates)
• Color filling required (painted text)
• Deep mark for wear resistance
• Thicker letter strokes for readability
• Decorative pattern with depth

Laser marking wins when

• Surface mark only (no dimensional impact)
• Very small text (under 1 mm)
• High-volume production speed
• Data matrix codes, barcodes
• No color fill needed

FAQ

Engrave depth specifications?

Standard 0.2-0.3 mm for visible markings. 0.1 mm minimum for shallow ID. 0.5+ mm for high-visibility deep engraving. Specify depth on drawing.

Color filling process?

After engraving, surface painted with chosen color. Paint settles into engraved depth. Excess wiped from surface. Engraved area retains color, surface wipes clean.

Multiple parts same logo?

Yes — once engraving program created, repeats for production volumes. Setup amortized over volume. Per-part cost low at volume.

Material limitations?

CNC engraves any machinable material — metals, plastics, wood. Hardness affects tooling and speed. Hardened steels need carbide tools, slower speeds.

Can curved surfaces be engraved?

Yes with proper CAM and 5-axis machine. Engraved on cylindrical surfaces for serial number, decorative work. More complex than flat engraving.

Depth uniformity on uneven surface?

Cast or rough surface produces uneven engrave depth. Pre-machine flat surface for engraving zone, then engrave. Or use lower depth tolerance specification.