I was installing a Siemens GFCI breaker in my main panel yesterday and had trouble
Torquing it's HOT side screw. The screw type was the one with a slot on top, and
A square grove in the middle (please see the attached picture). The specified torque
Was 25 lbs-in. I used a flat head screw driver bit, and it just doesn't seem to grab the
Screw firmly enough to torque it properly. Later, I noticed that a square bit #2 fits
In the grove of that screw, but I was afraid of stripping the grove, since I haven't
Used that types of bit on a breaker before. To complicate this even further, there is
Just enough room to insert the screw driver bit in the area to tighten the bit in the
Dark with only a flash light marginally lighting the area (for safety I shutoff main power).
I like to add that, this breaker was around $40 with tax, so it is a very expensive
Breaker to damage its screw.

Here are my questions:
1.Is there a special bit for this type of screw?
2.What tool or technique would you recommend?
3.Is there a place I can just buy screws for breakers, in case they are damaged?

Thanks in advance
-Ab

Use the square bit. You can sometimes find longer ones,

You can purchase torque scredrivers (expensive)

A conventional torque wrench will work with an extenson and a bit socket.

I have, on occaision ground the socket down so it would fir in tight places.

You can also try a bit driver with a socket at the end.

Here is a link for #1 and $2 bits up to 6" long:

Square Drive Power Bits - Rockler Woodworking Tools