Originally Posted by gpmbc
What do you mean not threaded?
Threaded, like in needing a specific type of machine screw in order to fit.
Originally Posted by baniels
I don't have access to measure, but they were big enough to accept these 1/4-20 bolts
without a washer. They didn't all appear to be perfectly round. I think I read of someone needing to add some washers so the head of his screw didn't go through. Can't remember what size or where I read that.
I've never seen threaded holes on a driver. That would force the use of t-nuts or threaded inserts for mounting, which I doubt would be popular.
Ok, so I need something around 1/4". Here in Germany, most everything in the hardware stores is metric. 1/4" is 6.4mm, so 6mm machine screws (I plan to use T-nuts) should work. I'd prefer 8mm, and if the hole is larger than 5/16, that could work. I guess I'll just have to wait until the drivers get here. It would be nice if a mechanical drawing of the HT18 subs was available. I probably won't start my build until the 15th of February, but there's a very good chance my drivers won't be here by then, and it would be nice if I was able to have exact measurements before I start cutting wood.