Way back, before all the "stuff" they do now in security, I was flying from SeaTac to Lax. I had been rock climbing so my pack was my only luggage. It was compact enough for carry on. Also, being me, I showed up maybe a half hour before departure. The pack was full of all kinds of metallic climbing gear. As was the protocol back then, they simply asked you if you have this that or the other thing in your carry on. I foolishly answered "yes" to the knife question. Security and a sheriff asked me to show it to them. It took ten minutes to dig it out. They said it couldn't be in my carry on. If I had more time I could have boxed it and put it in checked luggage. No time. The sheriff said he would do me a solid and mail it to me. So he took down my address and clipped the knife to his belt.
I never saw that knife again. Thanks