My local hardware store has a modest selection of expanding anchors. If I am free to drill the required hole, these anchors work great. But there are times when the hole exists and I just need to be able to thread in a bolt. That is where it is nice to be able to make my own anchor. The design presented here is not as strong as the store-bought variety.
If you are interested, please see
Your comments are welcome. All of us are smarter than any one of us.