There has been a lot of discussion recently about whether the TSA permits handcuffs on airplanes. Handcuffs are not addressed specifically in the prohibited items list. The TSA blog has addressed the issue and here is their thinking: "Some assumed handcuffs were prohibited, and were very surprised to find out they’re not. Why not, you might ask? They’re not a threat. You can’t do any real damage with a pair of handcuffs and if you really wanted to tie someone’s hands behind their back, there are many other ways you could do it." Here is the link: TSA Blog. I have personally carried handcuffs on planes on many occasions when going to trade shows without problems.