Files and formats
We accept STEP, STP, STL, DXF, DWG, PDF, JPG, JPEG, PNG and HEIC. Which one you should send depends on what you want made — and sending two files is usually better than sending one.
What we accept
STEP · STP · STL · DXF · DWG · PDF · JPG · JPEG · PNG · HEIC
STEP, STP and STL open in an interactive 3D preview when you upload them, so you can confirm the right part came across. Everything else is attached to your project for a person to review.
If all you have is a photo of a broken part or a sketch on graph paper, send that. It starts a conversation about design rather than a build, and that's a normal way to begin.
Which file for which job
A 3D part to be machined, formed, or re-toleranced — send STEP. STEP carries the exact geometry rather than an approximation of it, along with units, assembly structure, and any dimensional and tolerance information your CAD system attached to the model. If we need to adjust a feature, add machining stock, or work to your callouts, that information has to be in the file.
A 3D part to be printed — STL is fine. Printing ends in a mesh anyway, so an STL does the job. If there's any chance the same part later gets machined, molded, or modified, send the STEP too. It costs you one extra export now and saves recreating the model later.
A flat part to be cut — send DXF. Laser cutting and sheet metal nesting both work from 2D profiles, and DXF is the plainest, most reliable way to hand those over. Export the true cut geometry: closed profiles, no duplicate lines stacked on top of each other, no construction geometry or title block mixed in with the part outline. Bends and formed features still need a drawing or a 3D model alongside the flat.
Dimensions, tolerances, finishes, materials, notes — send a PDF drawing alongside the model. Never instead of it.
An idea, a reference, a sample, a part that failed — send photos. JPG, PNG and HEIC all upload. A photo with a ruler or caliper in the frame is worth more than a photo without one.
What each format keeps and what it loses
| Format | What it carries | What it doesn't | Send it for |
|---|---|---|---|
| STEP / STP | Exact curved and flat surfaces, units, assembly structure, dimensional and tolerance data where your CAD wrote it in | Your feature tree and design history — it's a finished shape, not an editable recipe | Anything 3D that will be machined, formed, molded, or modified |
| STL | A shell of triangles approximating the surface | Exact curves, units, color, material, tolerance data | 3D printing |
| DXF | 2D lines, arcs and profiles in a plain-text, well-documented structure | Meaningful 3D solids; anything the exporter flattened away | Flat cut parts — laser, sheet metal blanks |
| DWG | The same 2D drawing data in Autodesk's own format | A published specification — Autodesk has never released one, so every non-Autodesk reader is interpreting it | Drawings you can only export as DWG. Where you have the choice, DXF is the safer export |
| The drawing exactly as you see it: dimensions, tolerances, notes, finish callouts, title block, revision | Machine-readable geometry. A flat PDF is a picture of a part, not a model of one | The drawing that goes with your model | |
| JPG / PNG / HEIC | What the part looks like, and often what went wrong with it | Any dimension we can trust | Ideas, samples, references, failures |
STEP is ISO 10303, the international standard for exchanging model-based product data, and it's the format the whole industry uses to move parts between different CAD systems without losing the geometry. That's the whole reason it's the preferred one here.
STEP or STL, briefly
An STL describes your part as a skin of triangles. That's an approximation. A cylinder becomes a many-sided prism; a fillet becomes a series of flats. It's close enough to print and not close enough to machine to, because the exact surface a cutter needs to follow no longer exists in the file. STL also carries no units, so the same numbers can be read as millimeters by one program and inches by another — which is the most common way a part arrives at the wrong size.
Export settings control how finely the mesh approximates the real surface, and finer isn't automatically better: past a point you get a heavier file that prints identically. If STL is genuinely all you have, send it and say so. We'll tell you what's possible with it before anything gets made.
The full comparison, including what exactly gets thrown away in the export and how to set your tessellation, is here: STEP vs STL.
Send the model and the drawing
A 3D model says what shape the part is. It doesn't say which dimensions matter, what the surface finish should be, which holes are threaded, what material it's made from, or which edges have to break sharp. A drawing says all of that.
When only the model arrives, we build to the geometry and guess at the rest. When only the drawing arrives, someone has to recreate the model before anything can be quoted or cut. When both arrive, the model gives the geometry and the drawing gives the intent, and the two check each other — a mismatch between them is caught before it becomes a part.
Mark the few dimensions that actually control fit or function, put the rest under a general note, and say what the part mates with. That's more useful to us than a drawing where every dimension is called out equally.
Uploading a file is not a commitment. It starts a review. A person confirms feasibility, pricing, capacity and timing before we commit to anything.
If we can't use your file
Some files arrive damaged, empty, exported from the wrong configuration, or in a format the form doesn't take. That's routine and it's fixable. We'll tell you what we got and what we need instead.
Don't convert the file yourself first, and don't delete the original. A conversion can quietly drop the exact geometry, the units, or the tolerance data — the parts we most needed. Send what you have and ask.
If you're working from a format that isn't on the accepted list, call or email before doing anything to it. It's usually easier for us to tell you which export option to use than to reverse-engineer what a conversion removed.
Naming files and handling revisions
Put the revision in the filename, every time.
lower-bracket_revB.step— good.bracket_final_v2_NEW.step— a problem waiting to happen.
Two working rules:
- Never overwrite a file you've already sent. If the geometry changes, it's a new file with a new revision marker, not the same name with different contents inside it. Same-name-different-contents is how the wrong version gets made.
- Send the revised model and the revised drawing together, and make sure the revision letter on the drawing matches the one in the filename.
On our side, your project folder carries the folder structure and the revision name, and the revision appears on your final invoice, so there's a record of exactly which version was built. If something changes mid-job, request the revision through your dashboard. An employee confirms whether it's possible, and any change to time or price is emailed to you automatically.
Changes and reorders covers what happens next.
Before you upload
- The model, in STEP if the part will be machined or formed.
- The drawing, as PDF, alongside it.
- DXF for anything flat that gets cut.
- Material, quantity, and finish, if they're not already on the drawing.
- Photos of the sample or the failed part, if you have one.
Not sure which of these you have? Upload what you've got and we'll tell you what's missing.