Hi Frederick
If you don't need the threads, you can set the "Thread length" value to 0.
Here you can see this option both in ui and inside .htm file. (Line 97)
Also, "Angle" value controls the head and nut's fillet angle.
re:
> Can this kind of code be executed in a script file or must it be done in an .htm file?
It can go in either the .js file or the .htm file.
A long time ago (maybe V2 ?) there was a performance advantage to putting it in the .htm file which is why it's there. There isn't any difference anymore.
It's an impressive bit of work but it appears to only make plain head bolts - no socket head, pan head, button head, flat head - all with a hex recess for the Allen tool - and that is what I desire.