I just ran across this thread while looking for something else and wanted to make a comment. I travel regularly for work and often take short trips and only carry on my luggage.

I am not giving advice or stating that anything specific is allowed but I will comment on my experience.

For more than three years I have traveled with the Dovo shavette. The little light weight one with the plastic "scales". They say the handle is stainless steel but it is a very thin and light steel and the blade is held in with the red or black plastic. My thoughts have always been that if they pull my bag for this I will offer to toss out the actual disposable blade. As of yet they have not questioned my razor. Over the years I have traveled all over the USA and have gone thru many different airports. I am beginning to wonder if they can see that thin of a blade on the x-ray.