I have alway used machine screws to attach each of my radios and equipment single point to the earth ground buss bar (1/2" copper pipe) but today found an easier way.
Now I use pipe clamps used for grounding on water pipes for my attackment points.
The ground wire holes are are large enough to accomodate 3/4" tinned copper braid if folded and/or heavy gauge wire if desired.
This setup allows for movement or removal of a ground easily and quickly.
Though more expensive than a half dozen screws, the convenience is well worth it.
I thought I would share this idea.