Michigan law on carrying a knife.....
"MCL § 750.226
§ 750.226. Firearm or dangerous weapon; carrying with unlawful intent. Sec. 226.
Carrying firearm or dangerous weapon with unlawful intent-Any person who, with intent to use the same unlawfully against the person of another, goes armed with a pistol or other firearm or dagger, dirk, razor, stiletto, or knife having a blade over 3 inches in length, or any other dangerous or deadly weapon or instrument, shall be guilty of a felony, punishable by imprisonment in the state prison for not more than 5 years or by a fine of not more than 2,500 dollars."
So, if yer lawful in intent, yer good..