The study addresses the long-standing challenge of the strength-ductility trade-off in materials, particularly in steels. The researchers report a method to enhance the strength of twinning-induced plasticity (TWIP) steel without compromising its ductility. By applying torsion to TWIP steel samples, they create a gradient nanotwinned structure along the radial direction, doubling the yielding strength while maintaining the same ductility. This is achieved through the formation of a hierarchical nanotwinned structure during pre-torsion and subsequent tensile deformation. Finite element simulations based on crystal plasticity models confirm that the gradient twin structure increases strength and retains ductility by distributing plasticity and minimizing grain boundary deformation. The method's effectiveness is demonstrated through experiments and simulations, showing that it can be applied to various industrial applications, such as high-speed rail axles, where both strength and ductility are crucial.The study addresses the long-standing challenge of the strength-ductility trade-off in materials, particularly in steels. The researchers report a method to enhance the strength of twinning-induced plasticity (TWIP) steel without compromising its ductility. By applying torsion to TWIP steel samples, they create a gradient nanotwinned structure along the radial direction, doubling the yielding strength while maintaining the same ductility. This is achieved through the formation of a hierarchical nanotwinned structure during pre-torsion and subsequent tensile deformation. Finite element simulations based on crystal plasticity models confirm that the gradient twin structure increases strength and retains ductility by distributing plasticity and minimizing grain boundary deformation. The method's effectiveness is demonstrated through experiments and simulations, showing that it can be applied to various industrial applications, such as high-speed rail axles, where both strength and ductility are crucial.