Item 279
The Throwing Knife is a Ranged Weapon found in Underground Chests. '''''The Throwing Knife'' 'is favored by New Players, for they are mostly found in Underground Chests more near the surface, like in Tunnels. They do 6 damage each, which can kill a Green Slime in a single hit. The Throwing Knife's similar weapon is the Slime Knife, which is obtained from killing Green Slimes. The Throwing Knife can also be bought by the Vendor for 10 Bronze Coins for 5 of them, which makes them extremely useful for New Players. The Throwing Knife can be thrown until it hits something, and has a 10% to not break upon collision, thus making it re-collectable.

(Image from the Terraria Wiki)