Abstract: A laterally elongated miter rib is used as an internal fastener to attach two mitered members to one another. In the illustrative embodiment, the miter rib has two arms that are substantially orthogonal to one another. Each arm has a surface modification for improving the ability of the arm to grip the sidewalls of slots formed in the members. The arms have a length of around 1 inch, but have a greatly elongated lateral dimension that is typically equal in length to the members being attached thereby.