A clean CAD package is the difference between a quote in a day and a week of clarification emails. Here is what to send.
File format
A STEP (.step/.stp) or IGES 3D model is ideal—it carries geometry unambiguously. Add a PDF or DWG drawing for critical dimensions and tolerances the model alone does not express.
What the drawing must show
- Critical dimensions with tolerances
- Datum references for GD&T
- Thread specs (size, pitch, class)
- Surface finish requirements on key faces
- Material and any heat treatment
Notes that prevent mistakes
State quantities, target lead time, and any certification needs (material cert, CoC). Flag features that look important so the shop prioritizes inspection there.
Upload and go
Bundle the model, drawing, and any reference images in a ZIP and request a quote. Our engineering review confirms ambiguity before cutting.
FAQ
Is STEP better than STL? Yes for machining—STL is a mesh and loses precision. Use STEP.
Do I need a full drawing? For tight-tolerance parts, yes; for simple prototypes, the model plus key dims may suffice.
