To my knowledge, Indiana does not have a legal size limit for knife blades. 20+ years ago Indiana had a CCW Law, Carrying a Concealed Weapon that was so broad that we could arrest someone with a a pair of toenail clippers if they were in the wrong place at the wrong time doing the wrong thing. That law was repealed when the new Indiana Code took effect. It's possible that a new law has been enacted in the last year, but I seriously doubt it. That's why my curiousity of where in the Indiana Code that you saw that published.
Thanks,
sarge