I just flew last year and was actually 'allowed' to take on scissors that were less than six inch in length - the blade alone - I was shocked!! I had accidently left them in my carry on and when they found them they said they barely passed the length test but passed them with no fuss - a bit worrisome - I think the smaller ones should be ok, but the larger ones - hm-m--m makes me wonder what else gets through. Thread cutter - put a bobbin of thread in a dental floss container with the thread sticking out - voila - a way to cut thread on the plane!!)