Abstract: An anchor 14 for a building roof structure tie-down strap 12 comprises a rectangular hollow steel box 27 having a keyhole 26 formed at one end of one surface, which slips over the head 24 of an anchor pin 17 permanently fixed in the foundation 19 of a building, and a pair of bolt holes 29 formed at an opposite end in a pair of adjacent surfaces to receive a bolt 30 for fastening a strap-tightening ratchet 13 to the box 27.