The paper investigates the mechanical and superconducting properties of bilayer δ6 borophene (BL-δ6) using first-principles computations and anisotropic Migdal–Eliashberg analytics. BL-δ6, composed of two covalently bonded δ6 monolayers, exhibits remarkable mechanical properties with a maximum 2D Young’s modulus of ~570 N/m and superconductivity with a critical temperature (Tc) of ~20 K. The superconducting Tc can be further enhanced to ~46 K under applied strain, making it the highest Tc among all borophenes or two-dimensional elemental materials. The coexistence of strong covalent bonds and delocalized metallic bonds in BL-δ6 endows it with both superhard and superconducting properties, making it a promising material for various nanoscale devices such as quantum interferometers, superconducting transistors, and wear-resistant parts. The study highlights the potential of covalent metals in achieving high Tc superconductivity and the importance of considering anisotropic effects in predicting superconducting properties.The paper investigates the mechanical and superconducting properties of bilayer δ6 borophene (BL-δ6) using first-principles computations and anisotropic Migdal–Eliashberg analytics. BL-δ6, composed of two covalently bonded δ6 monolayers, exhibits remarkable mechanical properties with a maximum 2D Young’s modulus of ~570 N/m and superconductivity with a critical temperature (Tc) of ~20 K. The superconducting Tc can be further enhanced to ~46 K under applied strain, making it the highest Tc among all borophenes or two-dimensional elemental materials. The coexistence of strong covalent bonds and delocalized metallic bonds in BL-δ6 endows it with both superhard and superconducting properties, making it a promising material for various nanoscale devices such as quantum interferometers, superconducting transistors, and wear-resistant parts. The study highlights the potential of covalent metals in achieving high Tc superconductivity and the importance of considering anisotropic effects in predicting superconducting properties.