Part of a hinge for an aluminum chair. My grand uncle, who had one time won the lottery, designed a folding aluminum lawn chair. He manufactured the hinge parts first and sent them as samples of the work quality to retailers all over the world. He spent all of his winnings on the manufacture and mailing of these parts. Unfortunately the only order he got was from the CEO of Woolworths who was closing his business and needed a chair for the beach. I understand that CEO retired to New Hampshire. I believe you have found one of the hinges from Frank Woolworth’s chair.