I should have clarified that I brought my old broken handle into Home
Depot, Lowes and a specialty plumbing shop here in the Seattle area.
The plumbing "experts" at Home Depot and Lowes looked at the handle I
brought in and said "nope, we don't carry that" while the specialty
plumbing shop said that "standard" threaded handles are easy to find
while the larger diameter threaded valve handles (which is I guess what
I have) are tough to find. It's doubly tough to find when I don't even
know the proper name of what I am looking for. Does anyone know what
the correct name is for this "threaded" water valve handle so I can
call other plumbing shops or look online?

wrote:
I need to replace my water shut-off valve handle and am not sure where
to look or what to ask for. The standard plumbing supply stores seem
to stock only the square receptacle type whereas the one I have has
threads that the handle slips onto. My house is 40 years old and there
does not appear to be any name or manufacturer printed on the valve.
Thanks for your advice.