Part Design and Manufacturing Submission Guide
Design a bracket, flange or open box, export STEP and STL drafts, and prepare files and requirements for an engineer-reviewed manufacturing quote.
Updated September 28, 2026 · Maintained by Metal3D.ai
What is Metal3D.ai?
Metal3D.ai helps you develop a part design and request custom metal parts from China for global projects. Start with a supported AI design template or bring your existing CAD files. Manufacturing requests cover CNC machining, sheet metal, metal 3D printing, casting or forging review, CAD design, and finishing. Engineering confirms the manufacturing scope before approving a quote.
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What can I design with AI?
The current design workspace supports three parametric part templates, with dimensions in millimetres and an outer size of up to 500 mm:
- L bracket: specify outer length, width, height and uniform thickness. Additional holes and features are outside this template.
- Round flange: specify outer diameter, central bore, thickness and, optionally, up to eight bolt holes with their diameter and bolt circle.
- Open box: specify outer length, width, height and uniform wall/base thickness. A lid, extra cutouts and other added features are outside this template.
Assemblies, threads and freeform shapes are not supported. The workspace validates supported dimensions; a request outside these templates needs manual CAD design support. If AI design is shown as temporarily unavailable, use the CAD design request instead.
How do I create and revise a design?
- Open AI product design and sign in with an account whose email you have verified.
- Choose CNC machining or 3D printing as the intended process. Describe one supported part with explicit dimensions. For example: “An L bracket, 60 mm long, 40 mm wide, 50 mm high, with uniform thickness 4 mm and no holes.”
- Explicitly agree to send your description and selected process to the external AI model for design planning. Keep confidential information out of the description. This planning workflow does not send an uploaded CAD file to the model.
- Check the proposed dimensions. If dimensions are missing, add the requested details. Edit the parameters and confirm them before building the model; editing parameters does not call the AI again.
- Preview the generated model and download its STEP and STL files. After editing dimensions, build a new version; the previous preview and downloads continue to show the saved version until that new build succeeds.
Your designs and downloads are available through your account. The illustrative examples on public pages are separate from the model generated for your request.
What do the STEP and STL files provide?
STEP provides the generated solid geometry for further CAD work and engineering review. STL provides a triangulated model for preview and 3D printing preparation. These are design drafts: they do not provide CNC toolpaths, G-code, print settings, specified manufacturing tolerances, material certification or approval for production.
Confirm loads, interfaces, tolerances, material and process suitability with engineering. To request manufacture, download the files and attach them to a manufacturing request, along with any necessary drawings. The workspace does not automatically place a manufacturing order.
What should I upload for a manufacturing quote?
Provide a CAD model and the manufacturing requirements for each part. RFQ intake accepts STEP, STP, STL, 3MF, IGS, IGES, OBJ, DWG, DXF, PDF, and ZIP files. A PDF drawing is a drawing reference, not a 3D CAD model.
Include:
- Part name, requested process, material, quantity, and surface finish.
- 2D drawings for threads, critical dimensions, non-standard tolerances, cosmetic faces, or inspection requirements.
- Delivery country, target lead time, and the intended use of the part.
- Assembly interfaces and any dimensions that must be reviewed by engineering.
If a material or finish is undecided, say so. Engineering can ask about strength, temperature, corrosion, appearance, or cost requirements.
Why does a manufacturing request need engineering review?
After submission, the project workspace shows a preliminary summary: missing inputs, follow-up questions, and manufacturing considerations. Local rules check supplied requirements and file roles, such as whether a CAD model or tolerance drawing is present, whether material is undecided, and whether rush delivery or tight tolerances need discussion.
These checks do not establish that CAD geometry is manufacturable. They do not prove wall thickness, validate dimensions, guarantee a material, or confirm a price. Geometry analysis and engineering validation require separate review.
New manufacturing requests use local requirements checks and human review. They do not offer an external AI summary option. Existing project records may retain earlier summary sources and consent history; an earlier summary is not approval of the current scope.
How should I handle confidential project information?
An NDA request flags a manufacturing project for human handling; it does not itself sign an agreement. Contact the team before submitting data that needs a separate confidentiality arrangement. An NDA request on an RFQ does not cover text you separately choose to send through AI product design.
Historical external RFQ summaries could use project descriptions, customer notes, part specifications, file names and file roles, and local summaries, subject to the recorded consent and compliance conditions. That summary path did not send raw CAD file contents or geometry metadata. Keep these historical records distinct from the current design workflow. Review the privacy policy before sharing data.
How can I answer follow-up questions?
Sign in with the verified account that owns the RFQ. Reply to individual engineering questions or add a project requirement. Required questions stay open until an engineer reviews the current inputs and records a decision.
Adding a requirement refreshes local checks and starts a new review. Before checkout begins, you can supplement files, edit existing part specifications and select current or historical scanned files. The project preserves the before/after scope. Changes reopen engineering and compliance review and pause the old quote; a reviewed replacement needs a new customer confirmation.
The editor changes existing parts; adding or removing project parts and changes after checkout need team assistance. A payment record or manufacturing order blocks direct scope edits.
Who confirms price, feasibility, and lead time?
Engineering reviews the files and requirements and confirms the scope with manufacturing partners. The final quote states the approved price, lead time, finishing and inspection scope, shipping assumptions, and payment terms. A preliminary summary is not a production commitment or a final DFM report.
Regulated, certification-sensitive, or restricted-use projects need separate compliance and capability review and may be declined.
What happens after the quote?
Review the issued scope, file revisions, part prices, lead time and terms. Compare changed fields with the prior published version, then explicitly confirm the version you approve. Confirmation does not mean payment has been received. Manufacture, inspection and transport commitments are confirmed for the specific order.
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