I've been doing a lot of tanto style knives lately, mostly because I believe in the design. About twenty years ago a cutler named R.J. Martin wanted to know why the tips of Japanese knives and sword pierced so well.
It turns out that peasants without computers found that "drag points" made it more difficult for the Samurai to pierce his combatant's armor. Limit the drag points, polish the tip, and the entire knife or sword slides through the media--in the katana owner's case, a charging enemy Samurai...
Other than TOPS or Emerson-Protech, most tanto knives seem to be sharpened to create cosmetics that cover the errors. Put a stone on a "pretty" tanto and within minutes you find that all four bevels are differing angles and depths. It was driving me nuts.
Below are the special shaping tools, one in 60 grit, one in 140 grit to match my existing shaping tools. They are two inches wide with solid aluminum mounting backs to keep the shapers from flexing.
One of the pictures has a 'normal' shaper between the two behemoths!
As usual, Ken's work is accurate, dead flat and attractively priced. I cannot wait to get a twisted tanto in my greedy little mitts!