Injection Molding
Tooling and molding for your repeat plastic parts.
YOUR DRAWING. YOUR QUESTIONS. YOUR APPROVAL.
DFM FAQs Resolve Your Manufacturing Design Review Questions Before the Quote
Use these DFM questions before requesting a quote to clarify CAD, drawing requirements, critical features, materials and proposed changes. Identify what your supplier needs to review for your actual part.
Can a 3D CAD Model Replace a 2D Manufacturing Drawing?
Not automatically. A model may define nominal geometry; a drawing or an agreed model-based definition can communicate additional product requirements. Confirm whether embedded PMI, notes and acceptance information are complete, readable and accepted for your order.
| Information | Where it may be defined | Question to resolve |
|---|---|---|
| Nominal geometry | Model surfaces and features. | Confirm the required model version and delivery format. |
| Critical dimensions | Dimensions and datums in the agreed definition. | Identify which characteristics control fit or function. |
| Tolerances | Drawing or agreed model-based definition/PMI. | Confirm the tolerance basis and any referenced standards. |
| Material & finish | Full specification and controlled notes. | Identify grade, condition, treatment and protected faces. |
| Revision & acceptance | Controlled reference and agreed order records. | Resolve conflicts and name the approved baseline. |
This is an information comparison, not an inspection result. Your agreed drawing/model definition and order requirements govern.
Further reading: ASME digital product definition topics · Protolabs explanation of PMI. These references do not establish LK MFG capability or a required standard for your order.
Manufacturability Questions for Suppliers
Which features need review?
Identify deep pockets, narrow corners, thin walls, long holes, threads and difficult tool access on your drawing.
Which dimensions are critical?
Connect dimensions and datums to mating components, contact surfaces and functional requirements.
What happens if a feature changes?
Ask for the proposed change and its implications. Review function and acceptance before approving a revised baseline.
Your Material and Finish Questions Need the Full Specification
Can a familiar material name be used alone?
Provide the grade, condition, governing specification and product form that apply. Do not assume another regional designation authorizes substitution.
Does the finish affect your interfaces?
Identify contact faces, masked areas, fit, appearance and required surface condition.
Can a supplier use an alternative?
Define whether alternatives are permitted and who must approve them. Agree any required material or process evidence.
Use a DFM Checklist for Custom Parts Buyers to Control the Handoff
01 · Identify
Record the drawing revision, questions and proposed alternatives before sample manufacture.
02 · Agree
Confirm the accepted geometry, material, process and required checks with the responsible contacts.
03 · Preserve
Carry the approved baseline, sample limitations and change approvals into the production order.
A DFM review supports manufacturing planning. It does not by itself validate your application or approve an undocumented design change.
Review production release evidence →6 Inputs for Your DFM Discussion
- CAD and controlled drawing or agreed product definition.
- Part function and mating-component interfaces.
- Critical dimensions, datums and acceptance requirements.
- Full material, finish and permitted-alternative requirements.
- Prototype quantity and expected repeat demand.
- Required records and design-change approval contacts.
Answers Before You Send Your RFQ
What files should I send for DFM review?
Share CAD and the controlled drawing or agreed model-based definition, material/finish requirements, critical interfaces, quantity and required acceptance information.
Can a 3D CAD model replace a 2D manufacturing drawing?
Only where the agreed product definition communicates all required geometry, tolerances, notes and acceptance information in a format both parties accept. Clarify missing or conflicting information before release.
Does a DFM review guarantee every dimension can be made?
No. Review the specific geometry, material, process and inspection requirements. Resolve open points and agree the manufacturing scope.
Should I loosen every tolerance to reduce cost?
No. Connect each critical tolerance to fit or function. Review only proposed changes that preserve the required design intent and obtain the necessary approval.
Does an accepted sample approve repeat production automatically?
Identify what the sample demonstrated, what differed from production and which records or approvals are still required.
Can a supplier modify the drawing during prototyping?
Ask for proposed deviations and obtain the required approval. Keep the released drawing, sample reference and production baseline aligned.
DFM Guides → · Prepare your RFQ → · Review illustrative applications →
