Hmmm... I could sharpen up old 11T, 12T, 14T, 16T, 18T, 21T, 26T, 32T cogs. Trouble is, they could throw them back!When I was a kid was a fan of 'The Master' TV show with Lee Van Cleef. We made shuriken stars that were dangerous as ****, 4 really heavy duty sturdy razor blades and black tape was all it took to make one with 8 very sharp points that would stick in to wood from distance.