Provides you with technical, engineering, and scale models.
GrabCAD Community Library is a free repository built by working engineers rather than hobbyists. Most of what's in there is real mechanical CAD: brackets, gearbox housings, jigs, fixtures, whole assemblies.
The breadth comes from millions of engineer-contributed files, and a lot of them are true parametric/solid formats like STEP rather than just STL, which matters when a part actually has to mate with something.
Best for a mechanical or product designer who needs an engineering-accurate reference part, not a 3D artist looking for a pretty render asset.
Downloads are free but require creating a GrabCAD account first; formats include STEP, DWG, RVT and SKP depending on the uploader.
