Hi Frederick, yes having the threads does take a lot of computation. It is good to remove those if you don't really need them.

You can also find more prebuilt models for bolts and fasteners at McMaster-Carr's web site: https://www.mcmaster.com/

re:
> there didn't seem to be enough code in the JS to do all that is does.

Most of the code for this one is inside of the .htm file.

- Michael