A baseball bat is a long, thin piece of wood or metal used in the game of baseball to hit the ball and make it move. It's usually made from a single piece of solid material such as ash, maple, bamboo or aluminum and has a diameter of about 2.5 inches (6 cm) with a length between 30-34 inches (76-86 cm). The bat is swung by the batter to hit the ball thrown by the pitcher in an attempt to run around the bases and score runs for their team.