A steering section for guided munition comprises a steering body having n control surfaces folded inside or deployed protruding from the external surface. The steering section comprises a locking mechanism for the n control surfaces folded inside the steering body having a lock support secured thereto, a fixed sleeve secured to the lock support comprising a locking barrel, a mobile sleeve surrounding the fixed sleeve and slideable longitudinally along the locking barrel, the mobile sleeve comprising, on the outside of the fixed sleeve, a free end collaborating with the n control surfaces to keep them folded inside the steering body, a translational-locking device locking the translational movement along the mobile sleeve along the locking barrel deactivatable by unlocking force to trigger translational sliding movement of the mobile sleeve along the locking barrel and release the n control surfaces which can then move from their folded position into their deployed position.