The steel nails used for internal fixation after a fracture are in the vast majority of cases made of titanium, which means that they are made of titanium. Most of them are made of pure titanium, some are made of titanium alloy, but at present more than 99% of steel nails are made of titanium, only a very small part of them are made of steel. The steel ones are heavier than the titanium ones, but they are much less histocompatible, so they have been largely eliminated. The mainstream steel nails for internal fixation are made of titanium and have many distinct advantages, such as good histocompatibility, lighter weight, and better resistance to torsion and damage.