From the Super Mario Wiki
Screw Attack in an important item in the Metroid series. They are also used as weak items in the game Super Smash Bros. Melee. If the players press A near a Screw Attack, they pick it up. If the players jump with one in their hand, the jump is very similar to Samus's third jump, which is also named Screw Attack. Also, if there is another player around the player who jumps with a Screw Attack, that player takes minor damage.
These items can also be thrown at another player for minor damage, though the jumps often lead to combos. Also, when thrown, anyone it hits will automatically perform a Screw Attack. Although this hurts them, if they are close to other players when hit, they will hurt them as well. Afterwards, the target that got hit by the thrown Screw Attack will enter a helpless state.
The item returns in Super Smash Bros. Brawl. However, when it is picked up, it attaches itself to the player, much like the Franklin Badge. This allows players to use the Screw Attack's powers while using another item, but it does not allow players to throw it at others.
 Trophy Information from Super Smash Bros. Melee
 Trophy Information from Super Smash Bros. Brawl