I reckon Currawong has nailed it pretty well.
As for getting through terminals, unless you are flying or paxing on a prescribed air service there is no requirement for you to be subject to the screening process. So the only other way you are likely to get done is the unlikely event that there is some sort of airside inspection regime in place. Never seen it at any of the Security Cat 2 or Cat 3 airports that I have flown into.
I have always had a leatherman in my flight bag. In the bad old days before the regulation requiring all aircraft departing off the same apron as the screened service to also be screened was amended, I used to just leave said tool in the aircraft. It was a ridiculous regulation that took a lot of work to have amended to a more common sense approach.