In case anyone wants to know, here's what happened with my carry-on cross stitch supplies when I went to China last month:
I carried on a pair of Fiskar's with 3" blades, and they were accepted from Chicago to Detroit, Detroit to Tokyo, and then Tokyo to Beijing. I was assured they would be OK internationally by my co- worker, who flew to and from Canada a few weeks before, with no problem with 3" blades on her scissors.
However, China didn't like them. When I got on a domestic China flight (from Beijing to Xi'an), the security agent took them and said, "no scissors". She wasn't moved when I told her that I flew all the way from America with them the week before, they were even OK on the Tokyo to Beijing flight. She kept saying, "no scissors". Fortunately, I had a Clover Cutter in the same bag as the scissors, and those were OK. The security agent didn't even look twice at it. Which is the whole point behind a Clover Cutter!
I also had some metallic threads. This same security agent fingered them (I'm sure her hands weren't clean, but what was I going to do?), asked, "this metal?". I thought fast, realized if I used the word "metal", she'd grab those too. So I said, "thread". She said, "metal?", and I said, "thread". Then I demonstrated a sewing motion, kept saying "thread". She finally understood, and she let me get on the plane with the metallic threads.
I guess metal isn't allowed on planes in China, but I would assume that means no metal guns, or metal knives, or metal hand grenades. What evil could I do with metallic threads? But, like I said, I knew I had better not call them "metallic threads" or she'd confiscate those too, with my Fiskars.
It must be different, country by country. If you travelling internationally, don't forget to check each country's rules as far as what can be carried on their planes.
Audrey