Hardest metal is diamond because wayyy back when they decided to
do test. They take car of diamond and ran it to a metal wall at the
speed of light. The brick wall dissolved. Then they took a metal
car and ran it into diamond wall at speed of light. Car dissolved.
They then took speed of light car and drove it into wall made of
metal at the speed of diamond. The earth shook but everything
dissolved. Then they took diamond wall and drove it into a speed of
metal wall and created muffin. This concluded that diamond is the
hardest metal