Recommended formats
For flat parts, the most useful file is a 2D vector file, usually DXF or DWG. For parts with bends, shaped faces and relationships between features, send STEP or STP. A technical PDF is useful as a reference for critical dimensions, tolerances, threads, finish and visible surfaces.
| Part type | Recommended format | Notes |
|---|---|---|
| Flat cut part | DXF, DWG | Closed contours, with no dimensions on the cutting layer. |
| Bent sheet metal part | STEP, STP plus PDF | Sheet metal model with real thickness and defined bend radii. |
| Welded assembly | STEP plus PDF drawing | Include part positions, welds, material and functional tolerances. |
Rules for any file
- Work at 1:1 scale and use mm for dimensions, thicknesses, radii and distances.
- Keep only the part geometry in the file and remove title blocks, notes, dimensions, hatches and hidden objects.
- Specify material, thickness in mm, quantity and finish clearly.
- Mark critical dimensions, visible surfaces and assembly areas separately.
- If the project requires ISO 2768, EN ISO 9013, EN ISO 2553 or another standard, state it in the drawing or request.
Rules for DXF/DWG
Contours must be closed, with no overlapping lines, no unnecessary tiny segments and no duplicated elements. Text, logos and graphics must be converted to curves or outlines.
- Do not use common-line cutting between two parts; leave space between contours for cutting and handling.
- Avoid holes smaller than the material thickness, especially in thick sheet.
- Do not mix bend lines, engraving or construction lines with cutting lines unless the legend is clear.
Rules for STEP/STP and bent parts
For bent sheet metal, a STEP model is safer than sending only a flat pattern. The model should have constant thickness, real bend radii and planar faces.
Practical limits in metric units
- As a rule, minimum hole diameter should be at least the sheet thickness.
- Hole-to-edge distance should be at least 1 x material thickness.
- Holes too close to the bend line may become oval during bending.
- Overly tight tolerances increase cost and production time.
Checklist before sending
- DXF/DWG for flat parts or STEP/STP for bent parts.
- Dimensions in mm, at 1:1 scale.
- Closed contours, with no duplicated or overlapping lines.
- Material, thickness, quantity and finish stated clearly.
- Additional operations specified: bending, tapping, welding, deburring, powder coating, packaging.