A hinge assembly for mounting a toilet seat to a toilet bowl includes a hinge post, a bolt having a head and a threaded shaft configured to extend into a bore in the toilet bowl for securing the hinge post to the toilet bowl, and an adaptor having a first segment coupled to the head of the bolt, a second segment, and a shear segment connecting the first and second segments. The first and second segments are both configured to be engaged by a tool to rotate the bolt. The shear segment has a lower torque resistance than the first and second segments such that the shear segment breaks when a torque applied to the second segment reaches a predetermined amount. The head of the bolt is fit into the adaptor such that the first segment of the adaptor surrounds the head.
