Well, I’ve never heard the exact term “TSA Safe” before but I’ll assume it means the same as “TSA Approved”, which means that the tool was designed not to violate any of the rules about what can be brought through a TSA checkpoint, and that someone from the TSA reviewed the design and agreed that “yup, this doesn’t break any of our rules”.
However, the final decision about what is or is not allowed through a TSA checkpoint is always left to the discretion of the officers on duty, so being “TSA approved” is no guarantee that you won’t get unlucky with a TSA officer who’s feeling grumpy or hasn’t read the rules as closely as you have.
