I HAVE HUNDREDS OF TIE TACKS, TIE BARS AND CUFF LINKS. tie tack/bar: 1.46" x 0.57" (1-7/16" x 9/16" or 36.5mm x 14mm). collar bar: none. 0.25" = 1/4" or 6mm - pretty small for standard button holes. 0.38" = 3/8" or 9mm - also fits standard button holes.