According to IS : 13920, in beam web reinforcement, both the ends of the vertical stirrups of beams should be bent into a hook of

Indian Standard (IS) codes specify the detailing requirements for reinforcing steel in concrete structures to ensure adequate strength and ductility. For beam web reinforcement, particularly vertical stirrups, IS 13920 (Ductile Design and Detailing of Reinforced Concrete Structures subjected to Seismic Forces - Code of Practice) mandates a 135° hook at both ends. This specific hook shape is crucial for providing good anchorage and preventing stirrup pull-out, especially under seismic loads.