Petebass said:
You must have different T-nuts to the ones we get in Austr. Ours are designed to be hammered in. There's no other way to do it because the prongs face straight down. Yours sound better.
If you're worried about diging holes into your baffle board face, do what I do and put the T-nuts on the back of the front baffle.
I don't think they are different. Standard t-nuts with a barrel (internal threads), having a round, flat flange area with prongs that face the same direction as the barrel. They go in from the backside, the prongs bite into the back of the baffle board to keep the t-nut from turning when you tighten..
The problem is that when you hit them with a hammer, if that flat area you're hitting gets even slightly bent, the thread hole is already damaged. This actually happens quite easily, even more so if you use a C-clamp to try to press-start them. Everything looks just fine, but when you try to screw the bolt in, the threads are warped..
If one was going to hammer them in, it would be a good idea to screw the bolt into the threads to keep the barrel/threads from being damaged.
Using the bolt/washer technique, the t-nut starts properly aligned, and you tighten the bolt to draw the t-nut up tighly. The glue keeps them in there, and one won't push out the first time you remove the speaker and try to remount it.
On my last project, I used some threaded inserts that worked surprisingly well. They screw into the hole from the back side using a hex wrench, the flange on the back is smaller (less chance of any overhang), and they don't slip. They only require a slightly larger drill hole to install.
Another excellent alternative is the "hurricane" nuts I've seen at PartsExpress.com . These have barbs on the barrel instead of the flange. You tap these in with a hammer, and those barbs bite INSIDE the screw hole. They would probably be my next choice for a new project.
Mag...