Mesh in. The original CAD back out.
Every part below started as an STL. Untessellator turned it back into a STEP solid, and we checked that solid against the part's original CAD file, face by face: the same faces, of the same surface types, each within 1 µm of the original. That's the modeling tolerance the original file declares for itself.
What counts as a match
- Same solids. Our STEP has as many solids as the original, and each is valid and closed.
- Same faces. It has exactly as many faces as the original, and exactly as many of each surface type: plane, cylinder, cone, sphere, torus.
- One to one. Every face pairs with a face of the same type in the original.
- Within 1 µm. Points sampled on each face are within 0.001 mm of its partner's trimmed face, and the same holds in the other direction. The original STEP files declare an uncertainty of 10−6 m, so a match is as close as the original claims to be.
- Same volume, to within a 1 µm skin over the whole surface.
The input is the part as an STL, in single-precision floats like every STL. Every part page lets you download the STL, our STEP and the original, so you can check them in your own CAD.