I've used them for tying rebar, and they work really good, but they are a PITA because the pre-made wires come in a big roll and you need to remove each wire from the roll and then you need to wear a pouch to hold them in. They get all tangled up and are just clumsy. No one who ties bar for a living would use them for long. And the new ones they sell now don't even have a pointy hook, so that would even be worse.