Which Scissors and Other Sewing Supplies Are Allowed on Commercial Airline Flights?As of May 18, 2013, the Transportation Security Administration (TSA) Web site lists only a few prohibited supplies for anyone who would like to sew during a commercial airline flight.
Scissors"Scissors: metal with pointed tips and blades shorter than four inches" are allowed on a flight.
Since rules often change, and the ultimate decision of what either goes on-board or is confiscated is left up to each security post or airline, play it safe and take along nail clippers or a dental floss container to clip your threads and yarns. If you must take scissors, it might be best to stick with a blunt-nosed pair.
Any type of cutter with a blade should be stowed safely in your checked baggage (rotary cutters, of course, and all types of craft knives, even the teeny seam rippers that have cutting blades). The TSA doesn't mention restrictions against needles.
Knitting Needles and Circular Thread Cutters:The TSA's site says:
"Knitting needles are permitted in your carry-on baggage or checked baggage. Items needed to pursue a Needlepoint project are permitted in your carry-on baggage or checked baggage with the exception of circular thread cutters or any cutter with a blade contained inside which cannot go through the checkpoint and must go in your checked baggage."
Check the TSA's Web site for a current list of prohibited carry-on items. If you aren't sure about a specific item, call the security office at the airports where you must go through screening.