Abstract: Embodiments disclosed herein include fastener assemblies. In an embodiment, a fastener assembly comprises a sleeve with a hole, an inner surface, and top and bottom ends. The top end has a planar surface, and the inner surface has a cylindrical surface. The fastener assembly includes a fastener downwardly extending through the hole, and having a drive slot, a head, a shank, and a threaded region. The head is positioned within the bottom end. The head is separated from the threaded region by the shank. The fastener assembly comprises a cover disposed on the top end and having an access hole and top and bottom surfaces. The cover is welded to the sleeve to define an inner cavity between the cover, sleeve, and fastener head. The access hole is positioned over the drive slot. The cover, sleeve, and fastener comprises materials having high temperature, strength and oxidation resistances.