How to prepare a file for laser cutting
Short answer
Laser cutting needs a vector file — DXF or DWG preferred, drawn at real size (1:1 scale) in millimeters, with every contour closed and all text converted to outlines. Hole diameter must not be smaller than the material thickness, kerf on a fiber laser is 0.1-0.2mm, and parts need at least 1mm clearance.
Laser-cutting accuracy depends directly on the file you send us. An open contour, the wrong scale, or a raster image means the machine software either won't read the drawing at all or will produce something different from what you expected. This page collects the concrete requirements: which format we need, what scale and units to draw in, the minimum hole diameter, how much clearance to leave between parts, and how to separate cut lines from engrave lines in one file. The numbers here apply to fiber laser cutting on metal; for wood, acrylic and leather the format requirements are identical but the hole and clearance limits differ.
Key facts
- Recommended format
- DXF (AutoCAD 2000-2018)
- Accepted formats
- 6 formats — DXF, DWG, AI, CDR, SVG, vector PDF
- Scale and units
- 1:1, millimeters (not inches)
- Minimum hole (≥1mm stock)
- ≥ material thickness — 3mm hole on 3mm sheet
- Minimum hole (<1mm stock)
- ≈0.8mm — limited by the beam, not thickness
- Kerf (cut width)
- 0.1-0.2mm on a fiber laser in metal
- Clearance between parts
- ≥ material thickness, 1mm minimum
- Quote turnaround
- 24 hours from receiving the file
What file does laser cutting need — DXF or DWG?
A laser cutter reads a vector file — a mathematical description of lines, not pixels. A vector file is also called a drawing or a CAD file; these mean the same thing, and what matters is that the contours are stored as lines. The most trouble-free format is DXF (AutoCAD 2000-2018), which our cutting software imports directly. We also accept DWG, Adobe Illustrator (.ai), CorelDRAW (.cdr), SVG, and vector PDF. If the drawing was made in CorelDRAW or Illustrator, still export to DXF before sending — that avoids layer and font corruption between programs. JPG, PNG and BMP are raster files: they cannot be cut directly and must be converted to vector first, which takes extra time and often a separate fee.
- DXF — recommended, AutoCAD 2000-2018 version
- DWG, AI, CDR, SVG, vector PDF — also accepted
- JPG, PNG, BMP — not cuttable directly, needs vectorization
Why must the drawing be 1:1 scale with closed contours?
The drawing must be made at real size — 1:1 scale, in millimeters, not inches. A file that has been scaled up or down produces a part cut at the wrong size. The second condition is closed contours: each line must start and end at the same point, with no gap. With an open contour the software cannot tell inside from outside, and the cut comes out incomplete. Also delete duplicate and overlapping lines: a doubled line means the laser passes the same path twice, which burns the edge and adds cutting time. Before sending, run your program's 'join/weld' and 'overkill' functions, which find both faults automatically.
What is the minimum hole diameter for laser cutting?
On material 1mm and thicker the rule is simple: hole diameter must not be smaller than the material thickness. On 3mm steel sheet the smallest reliable hole is about 3mm; on 5mm it's 5mm. Below 1mm that rule stops applying, because the limit becomes the beam itself: the practical minimum is roughly 0.8mm. Try to go smaller and heat cannot dissipate fast enough — the metal melts at the hole edge and the hole either closes up or takes an irregular shape. If your project has many fine holes, such as a ventilation grid or decorative perforation, send the file ahead: we check whether the hole sizes suit the chosen thickness and, where needed, recommend thinner material.
How much clearance do parts need, and what is kerf?
The laser beam has real width — this is called the kerf, or cut width, and on metal with a fiber laser it averages 0.1-0.2mm depending on material and thickness. That means each edge of the part loses 0.1-0.2mm; if a piece has to press-fit into another, build that loss into the drawing in advance. Beyond kerf there is a thermal effect: two cut lines run very close together heat the metal and the part distorts. So between parts, and between a hole and an edge, we recommend clearance equal to the material thickness, but never less than 1mm. In a tightly nested drawing this spacing is exactly what determines how many parts fit on one sheet and therefore what the job costs.
How do I separate cut lines from engrave lines in one file?
If one part needs both operations — cutting the outline and engraving a logo — separate them by color or by layer. A widely used convention is red for cutting and black for engraving; we confirm the exact color coding when you place the order, so your own scheme also works as long as it's described in the file. Text must always be converted to outlines ('Convert to Curves' or 'Create Outlines') — if it stays as an editable font and we don't have that font installed, the letters shift or vanish from the file. This is the most commonly skipped step and the one that most often stalls file processing. Engraved characters on metal should be at least 3mm tall, below which legibility is lost.
What if the part needs bending?
This deserves a direct answer: we cut and engrave metal, but we do not bend it — a press brake, milling machine and lathe are not part of our equipment. If a part must be bent, we cut the flat piece and hand the bending to a vetted partner workshop. In that case send the drawing as a flat pattern, with bend lines on a separate layer and the angle noted — they must not be mixed into the cut contour. Keep in mind that metal stretches when bent, so the flat dimension is smaller than the sum of the finished part's sides; that allowance depends on the bend radius and we confirm it with the partner before cutting starts.
File requirements for laser cutting
| Parameter | Requirement | Note |
|---|---|---|
| File format | DXF (recommended), DWG, AI, CDR, SVG, vector PDF | JPG, PNG, BMP need vectorization |
| Scale and units | 1:1, millimeters | A file drawn in inches is off by 25.4x |
| Contours | Closed paths | Open contour = incomplete cut |
| Duplicate lines | Removed | 'Overkill' / 'weld' functions find them |
| Minimum hole (≥1mm) | ≥ material thickness | 3mm on 3mm sheet, 5mm on 5mm |
| Minimum hole (<1mm) | ≈0.8mm | Limited by the beam, not by thickness |
| Kerf (cut width) | 0.1-0.2mm | Per edge; build into press-fit drawings |
| Clearance between parts | ≥ thickness, 1mm min. | Prevents heat-related distortion |
| Text | Converted to outlines | Engraved characters — min. 3mm tall |
| Cut vs. engrave | Separate color or layer | e.g. red = cut, black = engrave |
How it works — step by step
- 1
Draw in a vector program
Use AutoCAD, CorelDRAW, Illustrator or the free Inkscape — any program that supports DXF export.
- 2
Set 1:1 scale and mm units
Draw at real size in millimeters. A drawing done 'approximately' or left in inches produces a part cut to the wrong size.
- 3
Close contours and delete duplicates
Confirm each line starts and ends at the same point, then use 'join/weld' and 'overkill' to strip overlapping lines.
- 4
Check holes and clearances
Keep hole diameter no smaller than material thickness (min. 0.8mm on stock under 1mm), and leave clearance equal to thickness but never below 1mm between parts.
- 5
Separate cut from engrave and outline all text
Move cut and engrave lines onto separate colors or layers, and convert every font to vector with 'Convert to Curves' / 'Create Outlines'.
- 6
Export to DXF and send it to us
Save as DXF (AutoCAD 2000-2018) or DWG and send it over — we check the file and return a price within 24 hours.
Frequently asked questions
Which file format is best for laser cutting?
DXF (AutoCAD 2000-2018 version) — our cutting software imports it directly with no conversion. We also accept DWG, AI, CDR, SVG and vector PDF.
Can I send a JPG or PNG file?
Not directly — these are raster, or pixel-based, formats and the laser cutter cannot read them. They must be converted to vector first, which takes extra time and often a separate fee.
Why does every contour need to be closed?
A closed contour means the line starts and ends at the same point. If a gap remains, the software cannot tell the inside of the part from the outside and the cut comes out incomplete.
What is the minimum hole diameter?
On material 1mm and thicker, the hole must be no smaller than the material thickness — about 3mm on a 3mm sheet. Below 1mm the beam sets the limit and the practical minimum is roughly 0.8mm.
How much clearance should there be between parts?
At least the material thickness, and never less than 1mm. This accounts for the kerf, or cut width (0.1-0.2mm), and the thermal effect that distorts parts placed too close together.
Does text need to be converted to outlines?
Yes, always. If text stays as an editable font and we don't have that font installed, the letters shift or disappear. 'Convert to Curves' or 'Create Outlines' solves this before you send the file.
My part needs bending — how should I draw it?
We cut metal but do not bend it — a press brake is not part of our equipment, so bending goes to a partner workshop. Send the drawing as a flat pattern with bend lines on a separate layer and the angle noted.
I don't have my own drawing — can I still order?
Yes. If you don't have a vector file, send us a sketch, a photo, or reference dimensions. A separate page covers how we build the DXF file from your input.