How to use the DFM check
Most rules are multiples of material thickness, so check that the thickness is right before you run the analysis.
Upload the part
STEP, STP or SLDPRT, modelled with a 3D sheet metal module. The tool reads thickness, bends and holes from the model.
Confirm material and thickness
Pick the material grade and correct the detected thickness (T) if needed.
Run the DFM check
You get nine design rules and six process limits, each marked Pass or Fail, plus any unfolding warnings or errors.
Komacut sheet metal design rules
These are the nine DFM rules the check applies, named as they appear in the analysis. They are the same rules the Komacut platform runs on every uploaded part. T is material thickness, R is inside bend radius, D is the required distance.
| Rule | Condition |
|---|---|
| Hole Size vs Thickness | T 0.5 to 10.0 mm: hole ≥ 0.6 × TT 10.0 to 20.0 mm: hole ≥ 0.4 × T |
| Hole to Edge | ≥ 2 × T |
| Bend to Radius | Inside bend radius ≥ T |
| Bend to Edge | D = 2.5 × T + R |
| Bend to Hole | Hole ≤ 25.4 mm: D = 2 × T + RHole or slot ≥ 25.4 mm: D = 2.5 × T + R |
| Hole to Hole | ≥ 5 × T |
| Hems | T ≤ 2 mm: inside diameter ≤ 2 × T and return length ≥ 4 × TT ≥ 2 mm: hem not possible |
| Countersink | Depth ≤ 0.6 × T; angle 30°, 45° or 60° |
| Corner Fillets | Radius ≥ 0.5 × T passesRadius below 0.5 × T is possible but leaves a sharp corner |
Process limits the analysis also checks
The second group checks the part against the size and feature limits of Komacut's equipment. Dimensional tolerances are listed on the process tolerances page.
| Check | Komacut limit |
|---|---|
| Max Product Size (Laser Cutting) | Sheet size by material (mm): Q235, Q355 1500 × 3000 · SAPH440 1260 × 2500 · SPCC, SGCC 1250 × 2500 · aluminium, stainless 1220 × 2440. Thickness up to 20.0 mm. See laser cutting. |
| Max Bend Length | Bending envelope 2400 mm length × 600 mm width × 10.0 mm thickness. Bend radius 1.0 to 16.0 mm. See sheet metal bending. |
| Max Surface Finishing | Part envelope by finish (L × W × H mm): powder coating 2400 × 1800 × 1200 · anodizing 1500 × 1000 × 400 · e-coating 1500 × 600 × 300 · brushed 1500 × 300 × 200 · zinc plating 1200 × 400 × 400 · passivation 900 × 800 × 400 |
| Min/Max Thread Size | Material 1.6 to 20.0 mm; part up to 400 × 400 mm unfolded; up to 3 thread types per part. See threading and chamfering. |
| Min/Max Chamfer Size | Angle 30°, 45° or 60° (±2°); width up to 6.0 mm; length up to 300 mm; up to 2 chamfer types per part |
| Min/Max Countersink Size | Depth ≤ 0.6 × T; angle 30°, 45° or 60°; up to 2 countersink types per part |
Warnings & Errors
The third group reports whether the model could be unfolded to a flat pattern, plus any warnings (for example "Small radius detected") and errors. A part that cannot be unfolded cannot be checked. Model it with a sheet metal module and upload again.
What a failed rule means
Fail means the feature is outside the limit in the table. Change the feature in the model and run the check again.
Once the part passes, check how the flat blank nests on a stock sheet with the Sheet Metal Nesting Calculator.
Bend to Hole
Move the hole away from the bend line to 2 × T + R or more (2.5 × T + R for holes and slots of 25.4 mm and above).
Hole Size vs Thickness
Enlarge the hole to at least 0.6 × T (0.4 × T above 10 mm thickness).
Bend to Radius
Increase the inside bend radius to at least the material thickness.
Hems
Use hems only on material of 2 mm or less, with a return length of at least 4 × T.
Frequently asked questions
What does DFM mean for sheet metal parts?
Design for manufacturing: checking a part design against the limits of the process that will make it. For laser-cut and bent sheet metal, the rules cover hole size, distances between holes, edges and bends, bend radius, hems, countersinks and corner fillets.
Which file formats does the DFM check accept?
STP, STEP and SLDPRT, modelled with a 3D sheet metal module. This is the same input as the Komacut instant quote.
Is this the same check Komacut runs on a quote?
Yes. The analysis is the one that runs automatically on every part uploaded on b2b.komacut.com. The quote also returns the price.
Which materials can I check?
The sheet metal grades Komacut stocks: cold rolled, hot rolled and galvanized steel, stainless steel and aluminium. The full list with properties is on the materials page.
What is the minimum bend radius Komacut can produce?
The inside bend radius must be at least the material thickness, within a tooling range of 1.0 to 16.0 mm. Air bending is the standard process. See sheet metal bending.
What happens to my file?
The file is used only to run the check. To keep the part and get a price, upload it on b2b.komacut.com.