I need to mount a shower valve on a crappy celcon block wall. I would be happiest with a machine screw into something metal bonded into the block as the shower valve is bloody heavy (about 5kg heavy - it's machined out of a solid lump of cast brass or something).
There isn't enough room to put a nut on a stud and I'd barely trust a screw into a brick wall let alone block.
One thought is to drill and tap a thick brass rod, but as I'd have to then buy a metric tap set, I was wondering if something ready made existed?
Threaded spacers came to mind, but they tend to be chromed and I don't recall seeing as big as M5 ish.