Why would it matter if you bring them across the border? Blades that short are not controlled weapons in either country. If they are not for commercial sale and are your personal property they are not any interest to a border guard. They may have questions, and you can easily give an answer by saying its your hobby and you're going to a meet-up.

My friend's dad once drove across the border with an old shotgun under his seat that he had forgot about. The border guys were cool about it and just let him turn back home. Not everyone in authority will act like a d*ck given the opportunity. Just don't be rude and obnoxious if they start to question you and you'll be fine.