Nailed it! Kung Fu master's Iron Fist doubles as hammer

Kung Fu master Yuan Hai demonstrated his ability to break bricks and hammer nails into pieces of wood with his bare hand.
Iron Fist, a variation of Iron Palm or Iron Hand, is one of the 72 arts of body training techniques known to the Chinese martial arts.
Mastering the method with hard training allows for the palm to deliver mighty blows without injuring the hand.