The Screw Attack is one of Samus's most powerful abilities. To find it in Norfair, you'll typically need to delve deeper into the region, often past areas that require the High Jump Boots. Look for a path that leads to a very hot, orange-colored section of Norfair. You'll likely encounter more challenging enemies and intricate platforming puzzles involving lava.
The Screw Attack is usually located in a large, open chamber. Once collected, Samus will gain a powerful, damaging aura during her somersault jumps. Any enemy she touches while performing a Screw Attack will be instantly destroyed (with a few exceptions). This makes navigating through enemy-infested areas much easier and provides a significant offensive boost. The Screw Attack also destroys certain types of blocks, opening up new paths. This is a game-changing power-up that will make the rest of your journey much smoother.