A fastener assembly (22, 612) for mounting a toilet seat to a toilet bowl (14, 604), the fastener assembly (22, 612) comprising: a threaded fastener (26, 616) having a first end portion and a second end portion; an adaptor (30, 620) having a first segment coupled to the first end portion of the threaded fastener (26, 616) to inhibit rotation of the adaptor (30, 620) relative to the threaded fastener (26, 616), a second segment (122, 696), and a shear segment connecting the first and second segments (118, 122, 696), the first and second segments (118, 122, 696) both configured to be engaged by a tool to rotate the threaded fastener (26, 616), the shear segment having a lower torque resistance than the first and second segments (118, 122, 696) such that the shear segment breaks when a torque applied to the second segment (122, 696) reaches a predetermined amount; a nut (38, 628) threadably coupled to the second end portion of the threaded fastener (26, 616); and a bushing (34, 624) positioned around a portion of the threaded fastener (26, 616) between the adaptor (30, 620) and the nut (38, 628); wherein one of the nut (38, 628) and the bushing (34, 624) includes an expandable section (140, 664), and wherein the expandable section (140, 664) has a surface (166, 676) that is engaged by a surface (158, 652) of the other of the nut (38, 628) and the bushing (34, 624) so that the expandable section (140, 664) expands as the nut (38, 628) moves relative to the threaded fastener (26, 616); and wherein the threaded fastener (26, 616) includes a bolt having a head at the first end portion, and wherein the head is fit into the adaptor (30, 620) such that the first segment of the adaptor (30, 620) surrounds the head. a threaded fastener (26, 616) having a first end portion and a second end portion; an adaptor (30, 620) having a first segment coupled to the first end portion of the threaded fastener (26, 616) to inhibit rotation of the adaptor (30, 620) relative to the threaded fastener (26, 616), a second segment (122, 696), and a shear segment connecting the first and second segments (118, 122, 696), the first and second segments (118, 122, 696) both configured to be engaged by a tool to rotate the threaded fastener (26, 616), the shear segment having a lower torque resistance than the first and second segments (118, 122, 696) such that the shear segment breaks when a torque applied to the second segment (122, 696) reaches a predetermined amount; a nut (38, 628) threadably coupled to the second end portion of the threaded fastener (26, 616); and a bushing (34, 624) positioned around a portion of the threaded fastener (26, 616) between the adaptor (30, 620) and the nut (38, 628); wherein one of the nut (38, 628) and the bushing (34, 624) includes an expandable section (140, 664), and wherein the expandable section (140, 664) has a surface (166, 676) that is engaged by a surface (158, 652) of the other of the nut (38, 628) and the bushing (34, 624) so that the expandable section (140, 664) expands as the nut (38, 628) moves relative to the threaded fastener (26, 616); and wherein the threaded fastener (26, 616) includes a bolt having a head at the first end portion, and wherein the head is fit into the adaptor (30, 620) such that the first segment of the adaptor (30, 620) surrounds the head.