What causes springback in sheet metal bending and how is it compensated?

Springback occurs when elastically strained material partially recovers after forming, causing the bend angle to open up. Factors affecting springback: Material yield strength (higher strength = more springback), Bend radius to thickness ratio (larger R/t = more springback), Elastic modulus, and Sheet thickness. Compensation methods: Overbending (bend past target angle), Bottoming/coining (plastic deformation at bend), Stretch bending (apply tension during bending), Optimized tooling design, and Simulation-based prediction. Springback can be 2-10 degrees depending on material; AHSS and aluminum alloys show significant springback requiring careful compensation.