Heavy bullion bars
Somebody may be quite surprised to hear that one of the best weapons to provide self-defense is to use something else than some kind of clubs, knives or even guns. There is nothing unusual in beating your opponent with such tools. The whole spirit of a modern hooligan lies deep inside in the ability of using anything that surrounds you. If you do not find yourself in possession of any gun or club or another sharp tool, you may just use something heavy to harm the aggressor. Supposing you are a worker of a big bank located in the suburbs and you are not armed when attacked. All you can use are the bullion bars made of gold and silver. They do not look dangerous but are quite heavy actually. If you have never held bullion bars in your hand you will be astonished by its weight the first time you hold it. It is a bit strange, but the density of the material makes it weigh so much. Bullion bars can be dangerous if you hit the opponents head with them. It may cause serious injuries or even lead to immediate death. So if you are a banker, remember that you always have some weapons available in the treasury if you really do not have anything else to fight with. Of course do not treat this text as a solution of how to deal with robbers.