When this applies
- The design exists as a 3D model only
- No formal drawing has been produced
- You want a manufacturability review before committing
- You are comparing processes for the same geometry
What the model does not say
Without a drawing or documented notes, the supplier must assume material, tolerance, finish and inspection. Those assumptions differ between shops, which is exactly why quotes diverge.
- Material and grade
- General and feature-specific tolerances
- Surface finish and coating
- Thread specifications and fits
- Inspection and documentation requirements
Ask for a manufacturability review
Most shops will flag features that add avoidable cost — deep narrow pockets, tiny internal radii, unnecessary tight tolerances. Requesting that feedback alongside the quote is free and routinely removes real cost from the part.
Keep the file and the requirements together
Even a one-page note listing material, tolerance and finish transforms a model into a quotable package — and gives you a reference for the second supplier later.
RFQ checklist
Include these in your request and suppliers can quote without a round of questions.
- STEP file plus native model
- A note or drawing stating material, tolerance and finish
- Quantity and target timing
- Request for manufacturability feedback
- Confidentiality requirements