Duncan, there's a pile of acrows rusting away in a pile and David's decided the owner's never going to use them now. None of them would be suitable for construction work. The threads will be fused with rust so the question will be how many will be usable for your purposes. He'll check them out later this week and we'll see if we can retrieve about 4 threads for you. We mightn't get 4 but I'm hoping for a couple at least.