The fastest RFQ is not the one with the most files; it is the one that removes guessing. The minimum set is a revision-controlled 2D drawing, 3D model for complex geometry, material and condition, quantity/lot pattern, tolerances and CTQs, finish, inspection documents, packing, delivery location and target date.
Values in this article support engineering screening during design review, RFQ and prototyping. They do not replace formal calculations, material data sheets, qualified procedures or contractual standards.
AN EXECUTABLE RFQ
The 2D PDF carries contractual dimensions, tolerances, datums, weld symbols and finish requirements. A STEP model supports geometry/programming but does not define unspecified tolerances by itself. “6061” is incomplete: distinguish 6061-T6 sheet, extrusion or another product form. State prototype, first lot and annual demand—for example, “5 samples, 100 first lot, 1,200/year released monthly”—so the supplier can select laser, stamping and tooling rationally.
CTQ AND TOLERANCE
Mark dimensions affecting safety, fit, sealing, location or regulation as CTQ and state inspection method. Do not apply ±0.05 mm everywhere; it can force secondary machining and 100% inspection. Use agreed general tolerances for ordinary sheet features; locate hole patterns with datums and position tolerance rather than chained ± dimensions.
RFQ CHECKLIST
- Files: PDF+STEP with consistent units, scale and revision. - Commercial: quantity, date, Incoterm/delivery point, currency and validity. - Technical: grade/condition, welds, finish, key dimensions and permitted substitutions. - Quality: FAI, material certificate, coating report, sampling/100% checks and labels. - Change: after quotation, reconfirm price, lead time and obsolete-material disposition for every revision.