How to prepare the right files for a quote

Why the files matter so much

When a shop prepares a quote, it looks at the part geometry, the material, which features are critical and how many parts are needed. All of that is read from the files and the request note. An incomplete package leads to one of two outcomes: the quote is delayed by back-and-forth questions, or the price is calculated cautiously to cover the uncertainty.

The goal is to give enough information that someone who has never seen the part could make it from the files alone. The ideal package is a 3D model together with a dimensioned technical drawing. The model describes the geometry without ambiguity; the drawing says within which limits that geometry is acceptable and what the part has to do.

Which format is for what?

Every CAD program has its own native file type. Instead of assuming the other side uses the same software, the safest route is to send neutral formats that any system can open.

STEP is the most widely used format because it transfers a solid model almost without loss. If you send your native CAD file, always add a STEP export next to it. IGES is an older standard and sometimes transfers surfaces that no longer join cleanly; if you can export STEP, use it.

STL and similar triangle-mesh files were designed for 3D printing. They do not store real geometry such as cylinders and planes, only small triangles that approximate them. For machining, hole centres and flat faces cannot be read reliably from that approximation, so an STL on its own is not a suitable quote file.

What should the drawing contain?

The 3D model answers the question “what does the part look like”; the drawing answers “when is the part correct”. A good technical drawing includes:

• Material: with its standard designation and grade (just “steel” or “aluminium” is not enough).
• Dimensions: every dimension needed to make and check the part, in a single unit system.
• Critical dimensions and tolerances: it should be clear which dimensions matter for the function.
• General tolerance note: which general standard applies to dimensions without an individual tolerance.
• Geometric tolerances (GD&T): form and position requirements such as flatness, perpendicularity, parallelism and position, and the datum features they refer to.
• Surface roughness: the required value on functional surfaces such as sealing, sliding or mating faces.
• Threads and holes: thread type, pitch and depth; fit or tapped holes.
• Edge and burr notes: requirements such as chamfered edges or no sharp edges.
• Weld symbols on welded parts: joint type, size and which side the weld is on.
• Title block: part name, drawing number, revision, scale and date.

What is a tolerance or GD&T callout?

No part can be made exactly to the nominal dimension; a tolerance states how much deviation is acceptable. Geometric tolerances describe shape and location rather than a single size: how flat a face must be, or where a hole must sit relative to another surface. They are written in a feature control frame with a symbol and datum letters.

Balance is what matters here. Putting tight tolerances on every dimension does not make a better part; it only adds machining and inspection time. Ask for tight tolerances only where the function needs them and leave the rest to the general tolerance note. Even one sentence explaining why a dimension is critical makes the quoter's job easier.

Assemblies and welded parts

If you are asking for a quote on a job made of several parts, do not send the assembly model on its own. Attach each part as a separate STEP file and show their positions relative to each other with an assembly drawing. File names that match the parts list on the assembly drawing make it easy to pair everything up.

For welded parts two pieces of information matter in particular: which parts are prepared before welding, and which surfaces are machined after welding. Because welding heat can distort the part, precise surfaces are often machined after welding. Stating this as a note on the drawing lets the job plan be set up correctly from the start.

What to write in the request note

The files describe the part; the request note describes the job. A short note covering the following points makes the quote noticeably more accurate:

• The quantity you need and whether the demand will repeat.
• Your material preference, or whether an equivalent material is acceptable.
• Where and how the part is used and which part it mates with.
• For welded parts, the surfaces that must be machined after welding.
• Your target delivery date, so planning can be discussed against it.

Common mistakes

• Model and drawing at different revisions. Check that both match before sending.
• Sending only screenshots. An image gives an idea but carries no dimensions.
• A PDF without dimensions. When there are views but no dimensions, the model governs; say so in a note.
• No material specified. Material affects both the price and the machining method directly.
• Sending a whole assembly in one file without saying which parts are to be quoted. List the parts you need.
• File names without a revision. A name like “flange_revB.step” prevents mix-ups.

Confidentiality

Drawings are often a company's most valuable information. Drawings you send to Innotech are used only to prepare a quote; on request we sign a non-disclosure agreement. Files uploaded through the quote form are not stored on the server; they are forwarded directly by e-mail to our quoting team.

Send us your files

Our quote form accepts STEP, IGES, DXF, DWG, PDF, ZIP, PNG and JPG files; you can upload up to 5 files and 20 MB in total per request. If your package is larger, compress it as a ZIP or write to us by e-mail.

If your model and drawing are ready, you can create a request in a few minutes with the quote form. If anything is missing, we will get in touch with you.