Die Cast Housing RFQ Checklist: Tooling, Machining and Inspection

Direct answer: a useful die cast housing RFQ should define the required material, annual and lifetime demand, controlled drawing revision, 3D model, functional interfaces, machining datums, surface finish, inspection evidence, packaging and delivery destination. These inputs allow a supplier to review the casting, tooling and secondary operations as one manufacturing route instead of quoting an incomplete shape.

Representative custom component. Material, dimensions, tolerances, finish and application are defined by the released buyer specification.

1. Identify the actual part and drawing revision

Send the latest released 2D drawing and a matching 3D model when available. State which document controls if the files disagree. The RFQ should identify the part number, revision, unit system, general notes and any customer-specific standards. Mark reference dimensions separately from acceptance characteristics.

If the design is still changing, tell the supplier which features are frozen and which remain under review. A quotation based on an uncontrolled model can create avoidable tool changes, sample delays and inspection disputes.

2. State material and final condition

Specify the required alloy or governing material standard and obtain buyer approval before any substitution. Also define the final condition, including heat treatment when applicable, corrosion exposure, coating or plating, operating temperature and any material-document requirements. A photograph or generic description is not a substitute for an engineering specification.

3. Provide realistic volume assumptions

Include prototype quantity, first production quantity, forecast annual demand and expected program life. These numbers influence tool concept, cavity strategy, production planning and the commercial comparison with other manufacturing routes. There is no universal volume threshold that makes die casting the correct choice for every part; geometry, alloy, machine size, yield, secondary operations and design stability all affect the decision.

4. Mark functional interfaces and appearance zones

Identify sealing faces, bearing fits, threads, connector interfaces, mounting points, cosmetic areas and any regions where gates, parting lines or ejector marks are restricted. If pressure tightness, leak performance or appearance is important, define the acceptance method and criteria rather than relying on a general note such as "good quality."

5. Plan machining with the casting

Many die cast housings still require CNC machining for bores, threads, datum faces, sealing surfaces or precision interfaces. The RFQ should distinguish as-cast and machined features, define machining stock where required and show the final datum scheme. Casting geometry, locating features, fixture access and inspection should be reviewed together.

The CNC machining tolerance and inspection guide explains why functional tolerances, datums and inspection methods should be separated from blanket tight tolerances.

6. Define surface finish and masking

State the finish type, color or appearance reference, coating standard, cosmetic zones, masking areas and any test or documentation requirements. Clarify whether threads, electrical contact areas, sealing surfaces or machined bores must remain free of coating. Packaging should protect the specified finish through international transport.

7. Agree on inspection evidence before tooling

Define which characteristics require first-article results, material or process documentation, traceability, appearance evidence, leak testing or other project-specific records. Inspection methods and acceptance criteria should be agreed before production tooling is released.

Use the first article inspection report checklist to connect the drawing revision, ballooned characteristics, results, certificates and disposition.

8. Include commercial and logistics inputs

A comparable quotation should state tooling, samples, recurring part price, machining, finishing, inspection, documentation, packaging, delivery destination and any assumptions that can change the price. Also clarify tool ownership, storage, maintenance, expected life assumptions and responsibility for design changes.

For a broader controlled submission package, use the custom metal parts RFQ checklist.

Questions a supplier should answer

• Which die-casting process, alloy and final condition are proposed?

• What DFM changes are recommended before tool release?

• Which features remain as-cast and which require machining?

• How will the tool concept address parting, slides, venting, overflow, ejection and trimming?

• Which assumptions support the quoted tooling and recurring price?

• What first-article, material, dimensional and traceability evidence is included?

• How will appearance, packaging and nonconforming product be controlled?

Request a die cast housing review

Email the latest drawing and revision, matching 3D model, material requirement, prototype and annual quantities, critical characteristics, surface finish, inspection documents, destination and target timing to info@castleintl.com. Castle Mechanical will review the available information and identify open manufacturing or inspection questions before quotation.

Frequently asked questions

Should an RFQ include both a drawing and a 3D model?

When both are available, send both and state which document controls. The drawing normally carries tolerances, notes and acceptance requirements, while the model supports geometry and DFM review.

Can every feature be produced as-cast?

No. Final datums, threads, sealing surfaces, bearing fits and other critical interfaces may require machining. The drawing and quotation should identify the final condition.

Is die casting automatically the lowest-cost process?

No. Tooling, alloy, geometry, machine capacity, yield, finishing, machining, inspection, demand and program life must be compared for the actual part.

When should inspection requirements be agreed?

Before production tooling is released. The controlled drawing, critical characteristics, inspection methods, first-article evidence and acceptance criteria should be aligned early.

What is the fastest way to receive a useful review?

Send a controlled drawing package with material, quantity, critical tolerances, finish, documentation, packaging, destination and timing instead of asking for a price from a photograph alone.