I HAVE HUNDREDS OF TIE TACKS, TIE BARS AND CUFF LINKS. tie tack/bar: 2.00" x 0.51" (2" x 1/2" or 50.5mm x 12.5mm). collar bar: none. I always try to point out any clear blemishes and condition. 0.50" = 1/2" or 12.5mm -this is fairly large for standard button holes.