The Briggs & Stratton 590808 Engine Crankshaft converts the piston's up-and-down motion into rotational motion to power the engine's moving components. It operates within the engine assembly and supports the transfer of mechanical power during operation. This replacement crankshaft can be used when the original is worn, bent, or damaged and requires repair. Check your engine model and... https://www.wholetoolbox.com/briggs-stratton-590808-engine-crankshaft/590808.html