My heartfelt condolences on the passing of your husband.
Traveling with human cremains presents no problem at all, but if you bring it with you in your carry-on luggage, it must be x-rayable to be allowed on the flight. The TSA suggests that you put the plastic bag with the ashes in a temporary receptacle that will allow x-ray, such as a box made of cardboard or plastic. Here is more information from a TSA website:
"We understand how painful losing a loved one is and we treat crematory remains with respect. Some airlines do not allow cremated remains as checked baggage, so please check with your airline to learn more about possible restrictions.
Under no circumstances will a Transportation Security Officer (TSO) open a crematory container. To facilitate screening, we suggest that you purchase a temporary or permanent crematory container made of a lighter weight material, such as wood or plastic. If the container is made of a material that generates an opaque image, the TSO will not be able to clearly determine what is inside the container and the container will not be permitted.
Even if an item is generally permitted, it may be subject to additional screening or not allowed through the checkpoint if it triggers an alarm during the screening process, appears to have been tampered with, or poses other security concerns. The final decision rests with TSA on whether to allow any items on the plane."
If the metal urn is lead-lined, it will not show any of the contents, when it goes through x-ray, which is not acceptable. If the metal urn is not lead-lined, there's still a chance, that being metal, it will not be able to be x-rayed to show the contents inside. A few inches of metal usually does not cause a problem. Also, don't forget that being metal, it might set off alarms at the check point. That's no problem, I'm just making you aware of the possibility.
While I realize you said you do not wish to repackage, it might be necessary in this case, to avoid any problems or additional screening at the security check point.
Again, my sincerest condolences and I wish you a good flight.
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