"Tom Gardner" Mars@Tacks wrote in message
...

I looked on the web and I'm NOT spending $3-5 apiece. I will cut
threaded rod and grind or mill a slot for a screwdriver if I can't
find a better solution. The plugs have to be easy and quick to
remove and install and keep the spoo out. Any suggestions?

I make male and female thread-holding plugs to fit in my 5C collets
from 1" drill rod and use a screw-in collet stop to set the length,
close enough for most applications.