If you go through the millimeter wave (back scatter is not used in the US anymore) body scanner it stands a very, very good chance to identify that something is there. Remember the body scanner is not a metal detector, it's a whats in your pocket detector. Plastic, metal, paper, pills, etc. It works by comparison "one of these thing is not like the other", it can't see through the body but from time to time it will pickup knee, hip, and pacemaker implants if it creates enough intrusion. Walk through metal detector would probably detect the metal but it wouldn't be enough metal to trigger a beep beep beep beep beep.
Being in the proximity to the groin this would likely trigger a groin anomaly resolution which is going to involve a pat down front and back up to and including inner and upper thigh, belt line in and out down to the knees, and then a swipe test of your hands. If they feel the pins during the pat down and they cannot make the determination as to what they are or they are unable to resolve the alarm they will ask you to show them the alarmed area in private screening for a visual determination. If your unwilling to resolve the issue with a visual inspection they will simply gather your belongings and escort you out of the checkpoint. Law enforcement is typically notified at that time and if they decide they want to talk to you they can pick you up from there. (And they usually do get you on the checkpoint before your escorted out)
What few people fail to read on the signs when they enter the checkpoint is that there is a point of no return. When you have submitted your property for x-ray screening, you have agreed to the be screened to completion and cant turn around and change your mind. If you fail to co-operate or submit to screening they will escort you and your belongings out usually to law enforcement. Once you have engaged the screening process your committed. No point in having a terrorist come in with a bomb, the TSA find it, and then the bad guy be like "well you caught me, I'm not telling you what it is I just wont go through today, see ya later this week when I try again"
Although harmless as a diaper pin is, they don't know that until they can determine that's what it is. Best to avoid a possible scanner alarm and switch to a disposable for the day. You can pat down a disposable diaper and know what it is male or female. If the hands pass the swipe test, good to go. A plastic pant and cloth diaper is not going to have the same feel and an officer may be unable to clear the area of alarm. Cloth diapers are kinda "retro" so it may raise suspicion to a younger officer.
Believe it or not, they are seeing less and less plastic backed diapers on the checkpoint. In a matter of a decade or so I wouldn't be surprised if plastic backed disposable diapers would raise the same suspicion cloth and plastic pants would at this time. But then again, maybe the screening technology will be better and the machines can clearly identify a diaper vs underwear with a device concealed under it.
Hope that helped
Just my advice unless you want to risk having to go through the process.
but I’ve been there many times. Love that part of Oregon, the high desert is really magical. Im in NE Oregon in the middle of nowhere.
