According the Federal Government and TSA, “we can’t be fully safe if people are freely walking around with ‘EVEN JUST’ a “classic two inch penknife”. So what’s the big deal?
I was at "The Gun Shop" in Idaho Falls last Saturday. They have a case with multiple knives labeled "INL Approved". That means an employee of Idaho National Labs can possess that knife on the INL grounds. All very short blades. My own employer has a "weapons" policy that is far less specific. Fortunately, I work from my home office, so I don't have to be concerned about what is permissible "at the office".