I HAVE HUNDREDS OF TIE TACKS, TIE BARS AND CUFF LINKS. tie tack/bar: 1.72" x 0.40" (1-3/4" x 3/8" or 43.5mm x 10mm). collar bar: none. I always try to point out any clear blemishes and condition. 0.25" = 1/4" or 6mm - pretty small for standard button holes.