I've been through US and Oz security with 2 x headset, 1 x stopwatch, 1x ICOM several times and only once got asked why. Answering "pilot" got a smile and a wave. However, last time I remembered at check in just in time to remove my fuel tester (sharp pointy thing on the end) and transferred it to checked bag.
I certainly wouldn't risk a nice leatherman as you've effectively lost it if/when its found at screening.