I made one today out of 1/2 rebar. It looks pretty good and does have a fair sound. One thing I did discover is that if I hang it from a steel ring it tends to deaden the sound. Too bad really cause I went to the trouble to make a ring I even got it to forge weld the joint on the 1st try. When I hang it from a string it rings lots better.

Added 4 minutes later:

One other thing I did was to quench the three corners. I don't know if it makes a difference or not but I'm thinking the harder the steel the more it will vibrate and since it is rebar it is likely that it has a fair amount of carbon in it.