I assume that they need to be a certain length too, and that the hardware that comes with the wall mount boom arm is not compatible...
Thanks Martin, I was just going to post that you said 10-32 earlier in the thread, I knew I had seen it somewhere. Looks like they can't be too long, like 1" maybe?
I'm not sure if it was in this thread or the home studio thread that we talked about this, but I'll throw this out again. I'm not sure what hardware you'll get with your boom arm. I bought a used one and it had no mounting hardware - but even if it comes with something, it'll probably be for wall mounting. No worries, you only use the holes in the mounting plate.
The screws I used are the sort that you can buy for attaching things to a bicycle frame. With the allen wrench heads. I have found them (here in Germany) in two lengths, and the longer one is too long - they bottom-out in the Super Clamp holes before the plate is tight. Martin and I discussed earlier, the holes are tapped for metric (M5, if I remember correctly) but 10-32 is essentially the same.
You might need a washer to keep the head from pulling through the holes.
When you find the right screws, by some extras to keep in your studio. The same screws can be used to put two Super Clamps together into a Double.