A quotation is only as accurate as the information it is based on. Every ambiguity in your drawing is a question that must be asked and answered before an accurate price can be generated — and every question adds at least 24 hours to the cycle. A complete drawing package eliminates ambiguity and enables a same-morning DFM review and next-morning quote. An incomplete one triggers a loop that typically takes 3–5 business days to resolve.
complete drawing package
incomplete submission
by missing material spec
1. Required: What Every Drawing Package Must Include
A dimensioned CAD file in a machine-readable format
DXF or DWG for 2D laser-cut profiles. STEP (preferred) or IGES for 3D formed, bent, or machined parts. The file must be to scale (1:1) with all features at final cut size — not nominal dimensions requiring interpretation. Do not submit only a PDF if the part will be cut; PDFs cannot be directly imported into cutting software without manual re-drafting that introduces transcription errors.
Full material specification with grade and temper
Write “SS316L, 2mm sheet” not “stainless steel.” Write “AL6061-T6, 3mm” not “aluminium.” Write “PI film, 0.05mm, black, adhesive-backed” not “film.” Ambiguous material specs default to the fabricator’s most common stock grade — which may not be what you need, and discovering the mismatch after production is expensive.
Quantity (prototype and/or production, clearly separated)
State prototype quantity and production batch quantity separately if you want pricing for both. “5 pieces for prototype, 200 for production” enables tier pricing to be quoted simultaneously. “Some pieces” or “a small batch” requires clarification before pricing can be generated.
Tolerance callouts on all critical dimensions
If you have a general tolerance (e.g., ±0.1mm unless otherwise noted), state it in the title block. If specific features have tighter requirements, call them out individually. A drawing with no tolerance information will be quoted to general fabrication tolerance — which may be insufficient for your application, requiring a revision and re-quote cycle after the fact.
2. Important: What Significantly Speeds Up the Process
A PDF drawing with all annotations, notes, and GD&T callouts
The CAD file contains geometry; the PDF drawing contains engineering intent. Tolerance callouts, surface finish requirements, thread specifications, datum references, and general notes are often legible only in the PDF. For any part with GD&T callouts or secondary operations, the PDF is essential.
Surface finish specification (Ra/Rz value or coating type)
If a specific surface roughness is required (e.g., Ra 0.8μm for a sealing surface), state it on the drawing. If a coating, anodising, or passivation is required, specify the standard (e.g., “anodise clear, per MIL-A-8625 Type II,” or “passivate per ASTM A967”). “Good finish” and “smooth” are not quotable specifications.
Required-by date at your Singapore facility
State the date parts must be at your facility, not the date you want production to start. This enables the fabricator to work backward from your required delivery date to confirm whether the timeline is achievable — and to flag potential conflicts before you have placed the order.
Documentation requirements (FAI, material certs, CMM report)
If your incoming inspection requires specific documentation — FAI report, full CMM dimensional report, material certificates, certificate of conformance — state this in the initial submission. Documentation requirements affect labour cost and should be reflected in the quote. Requesting them after parts are shipped often creates delay and in some cases cannot be fully accommodated retroactively.
3. The 8 Most Common Drawing Mistakes
| Mistake | What It Causes | The Fix |
|---|---|---|
| Material listed as “Stainless Steel” | Grade defaults to 304; must clarify before cutting | Write “SS304” or “SS316L” explicitly |
| DXF not to 1:1 scale | All dimensions cut incorrectly; parts scrapped | Export DXF at 1:1 from your CAD software |
| No tolerance block in title | Quoted to workshop tolerance (±0.5mm); may fail your inspection | Add general tolerance to title block |
| Bend lines missing from DXF | Flat profile is cut; bending cannot proceed without tool path | Include bend lines and add STEP file for 3D reference |
| PDF only, no CAD file | Geometry must be redrawn from scratch; transcription errors likely | Always include native CAD file alongside PDF |
| Thread spec missing | Tapped holes quoted to nearest standard; may not match your fastener | Call out “M5×0.8 through, 6H” explicitly |
| “As per sample” instruction | Sample cannot be measured accurately; dimensions must be confirmed by drawing | Provide a drawn part with all dimensions; use sample as reference only |
| Quantity listed as “TBD” | Pricing cannot be completed; order is held pending clarification | State exact quantity or a range with confirmation within N days |
4. Good vs. Bad Specification Examples
Material: “Stainless steel, 3mm”
Material: “SS316L, 3.0mm sheet, mill-certified”
// SURFACE FINISH
Finish: “Smooth, no scratches”
Finish: “Ra ≤ 1.6μm on mating face (face A); other surfaces deburr only”
// TOLERANCE
Tolerance: “As accurate as possible”
Tolerance: “±0.1mm general, ±0.05mm on hole positions”
// THREAD
Thread: “M5 tapped holes, 4 places”
Thread: “M5×0.8 tapped through, 6H tolerance, 4 places as shown”
// QUANTITY
Qty: “A few prototypes, then more later”
Qty: “5 pcs prototype, 100 pcs production (confirm within 30 days)”
5. Special Case: Multi-Part Assembly Submissions
When submitting a multi-part assembly for fabrication, additional information significantly speeds up the quoting process and reduces the probability of fit problems in production:
Include a top-level assembly drawing. Even a simple sketch that shows how the parts relate to each other — which surface mates with which, where fasteners pass through — allows the fabricator to check that individual part tolerances will result in a correct assembly. Without this, individual parts can each be within tolerance and still fail to assemble correctly.
Label parts with revision numbers. If you are submitting a revised drawing, mark it clearly with a revision letter and note what changed. “Rev B — hole diameter changed from 5mm to 6mm” prevents production of the wrong revision.
Identify which parts need to match. If two mating parts must be made in the same production run to ensure dimensional match — for example, a housing and a cover that are machined to achieve a specific gap — state this explicitly. It affects how the job is scheduled and inspected.
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