In article . com, "redbrickhat" wrote:
I recently opened up an old electrical box with a weak ground. To fix
the ground problem I wanted to connect a ground wire to a green
grounding screw into the box.

Not sure I understand... Why is the ground "weak"? And why do you believe this
will fix it?

However, the old box doesn't have any holes for 8-32 sized screws, but
only for the larger holes (for mounting?).

Questions:

A) Is there any reason why I cannot screw the grounding wire into one
of the larger holes in the box?

Code requires that the screw holding the grounding wire may not be used for
any other purpose. So if the hole you're proposing to use is already in use
for mounting the box, or attaching a cable clamp, then the answer is no.
Otherwise, yes.

Also no reason (given the appropriate tools) why you couldn't drill and tap a
new hole for standard 8-32 grounding screws.

B) What size screws fit the larger holes?

Usually 10-32.

C) Would any normal screw metal type work?

No -- you want a screw with a pan head, round head, or washer head. Flat head
and oval head will not hold the wire securely.

You'll find that something with a Phillips or Robertson (square drive) head is
easier to install than a slotted head.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.