As far as belts with metal buckles go, I knew a good martial artist who gave a review of a street fight involving that weapon.
What caught his eye was that the typical technique involved swinging two feet or more of belt length for intermediate range use, but in this case, the user wrapped his hand, leaving about a foot of belt length, and used it much like nunchaku.
And, he noted, used it very effectively, leaving his opponent’s face a bloody mess.
Yup. Multiple effective techniques exist using a simple belt with a metal buckle. Same goes for a solid body steel pen aka tactical pen.
I NEVER fly unarmed. But my weapons are perfectly legal to carry through TSA aka Security Theater.
BTW the belt is particularly useful against a knife...