A useful RFQ is not the longest email. It is the one that makes the part, commercial scope and acceptance criteria clear. For non-standard metal components, the drawing remains the primary source of truth, while the supporting details explain production volume, finish, inspection and delivery expectations.
1. Supply a controlled drawing
A 3D file helps the manufacturer understand geometry. A 2D drawing defines dimensions, tolerances, threads, surface requirements and notes that may not exist in the model. When possible, supply both.
- STEP or STP for 3D geometry
- PDF or DWG for dimensions, tolerances and notes
- A clear part number, drawing revision and unit system
- Only the current revision, or a clear explanation of what changed
A clear sketch can be enough for an early feasibility conversation, but a controlled drawing is normally required before production is confirmed.
2. State the material and grade
Do not write only "stainless steel" or "titanium" when the grade matters. State the exact grade required, or explain the application requirement if you need the manufacturer to discuss options.
| RFQ field | Useful information | Why it matters |
|---|---|---|
| Material | 303, 304, 316, 316L or 904-series stainless steel; brass; copper; titanium alloy; specified iron grade | Changes stock, machining response, finish and cost. Confirm the exact 904 grade in the RFQ. |
| Documentation | State whether a material record is required | Allows documentation scope to be reviewed before quoting |
| Substitution | Allowed, not allowed, or subject to written approval | Prevents an unapproved material assumption |
3. Separate prototype and production quantity
Quote requirements change when a one-off sample may become a 1,000-piece order. Include the quantity needed now and the likely follow-up volume so the process and commercial review can consider both stages.
- Prototype or sample quantity
- Expected quantity per production batch
- Estimated repeat frequency, if known
- Whether sample approval is required before batch production
4. Identify critical dimensions and interfaces
A blanket tight tolerance can add cost without improving function. Mark the dimensions that control fit, alignment, sealing, movement, weight or appearance, and distinguish them from general dimensions.
Zhenglong's typical capability can reach ±0.01 mm, but the achievable tolerance must be confirmed against geometry, material, size, process and inspection method for each drawing.
5. Define the required surface
Finish is both visual and functional. Use a reference sample, controlled image or measurable specification where appearance is important. State which faces are cosmetic and which surfaces mate, seal or move.
- As-machined, polished, brushed or sandblasted
- PVD or electroplated appearance and color reference
- Engraving, etching or stone-setting locations
- Surface roughness where it is functionally required
- Areas where tool marks, scratches or color variation are unacceptable
6. Define inspection and acceptance needs
Tell the manufacturer which dimensions require recorded results and whether material or inspection documentation is needed. This allows the measurement method and reporting scope to be reviewed before the quote.
Available equipment includes calipers, micrometers, height gauges, profile projection, optical measurement, CMM, roughness testing and hardness testing. The inspection method used depends on the feature and project requirement.
7. Add target date and destination
Lead time is affected by material, tooling, finishing, inspection, quantity and shipping destination. State whether the date refers to sample approval, factory completion or arrival at your location.
- Required sample date
- Production delivery target
- Destination country and city
- Packaging or part-protection concerns
8. Final RFQ checklist
Turn the checklist into an RFQ.
The quote page collects these fields for direct submission. If delivery fails, you can retry or choose an email draft.