Bluing (steel)

Bluing is when you make a piece of steel turn into a pretty blue color. People do it to make their knives or guns look cool. It starts by cleaning the steel very, very well. Then, you heat up the steel until it is very hot. When it gets hot enough, you put a liquid on it that has chemicals in it. The chemicals make the steel turn blue. Then, you clean off the liquid and you have a pretty blue piece of steel!