Beginner DFM Checklist
The ten-point checklist to run before you upload a part for quoting
Design for Manufacturing (DFM) is a pre-flight checklist: ten questions that catch most quoting surprises before they cost money — walls, draft, radii, threads, tolerances, text, depth, overhangs, material and finish. Running it before upload takes five minutes and typically cuts cost 20–50% while eliminating schedule risk.
1. The ten checks
1. Walls: above process minimums (0.8 mm metal, 1.0 mm plastic, 1.0–4.0 mm molded) and uniform. 2. Draft: 1–2° on molded faces. 3. Radii: internal fillets ≥ 0.5 mm. 4. Depth: pockets ≤ 4:1. 5. Threads: standard sizes ≥ M1.6, engagement 1.5–2×.
6. Tolerances: general ±0.127 mm unless function demands; tight only on mating features. 7. Text: ≥ 0.8 mm or laser mark. 8. Overhangs: ≤ 45° for printing or oriented to supports. 9. Material: cheapest grade meeting service conditions. 10. Finish: match spec to function, one pass per operation.
2. Before you upload
Export STEP (AP214) from native CAD; check units (mm) and scale; set the coordinate system to the datum scheme; remove reference bodies and sketches; verify the part is a solid (watertight).
Decide the process by quantity and geometry (see Manufacturing Methods); enter or confirm L/W/H; choose material from the library; state finish, tolerance class and lead time. The engine flags residual issues on upload.
3. Red flags on the quote
A quote with DFM notes means risk: read them (deep pockets, thin walls, tight tolerances) and fix before ordering. Unexpectedly high per-unit cost on small simple parts usually means setup/minimums — order the tier or consolidate.
If the engine’s volume/bounding box differs from your model, correct it — the whole quote is built on it.
4. The habit
DFM is iterative: quote, review, redesign, re-quote. The live calculator makes each iteration instant, so tighten the loop until the price matches the function — then freeze and order.
Keep the checklist with your CAD template; teams that run it mechanically quote 20–50% cheaper and hit schedules.
Quick reference
| # | Check | Pass condition |
|---|---|---|
| 1 | Wall thickness | Above process minimum, uniform |
| 2 | Draft | 1–2° on molded faces |
| 3 | Internal radii | ≥ 0.5 mm fillets |
| 4 | Pocket depth | ≤ 4:1 depth:width |
| 5 | Threads | ≥ M1.6, standard, engaged 1.5–2× |
| 6 | Tolerances | General unless functional |
| 7 | Text | ≥ 0.8 mm or laser mark |
| 8 | Overhangs | ≤ 45° or supported |
| 9 | Material | Minimum adequate grade |
| 10 | Finish | Matched to function |
Sources & references
- ISO 2768-1 — General tolerances
- DIN 16742 — Plastic tolerances
- Xometry Learning Center — DFM Checklist (public engineering reference)