Get a steel one, but to get into most places to use the key you need other lock opening devices. The lowest one is best to open as water and gravity. They will bee in high rises with multi story parkade basement or and under manholes. This is a confined space know what saftey stuff you will need to enter or it can be a one way trip. Getting a realtor key and a city works key help acess are not super easy to come by. You will also need saftey hardware removal tools as many of the silcock taps are in secured cabinets to stop homeless from opening them with blunt object.
@namelus When I was growing up in the 50s and 60s I remember seeing the outside silcocks/faucets as just needing a tool to turn the faucet. But I have seen more recently them having a metal plate/door over the faucet itself. Your suggesting that requires a different key. All I know to do is buy a couple of different keys and hope they work when I need them. If I try them out my luck would get me arrested and draw attention to myself as a prepper. Can’t have that.
@Tolk, Yeah, pretty much every non-single family dwelling in the last 60+ years.
There is one less risky way to try, look up urban exploration in your area and try in one of those buildings.
If you do tell someone where you are going and return time, bring gloves mask silcock key and headlamp and flash light. Mask is for the moulds in all abandoned buildings, gloves well it’s an abandoned site. There are trespass laws but a minor issue as cops don’t usually attend as it’s abandoned.