Texas State Penal Code 46, it deals with weapons, and a search of
http://www.statutes.legis.state.tx.us/docs/PE/htm/PE.46.htm will give you the full scope of the code. But, I will post a relevant excerpt from the code.
(6) "Illegal knife" means a:
(A) knife with a blade over five and one-half inches;
(B) hand instrument designed to cut or stab another by being thrown;
(C) dagger, including but not limited to a dirk, stiletto, and poniard;
(D) bowie knife;
(E) sword; or
(F) spear.
Hope this clears it up for ya'll. I find it unfortunate, as I carry a Bowie.