TSA Bans This Knife At The Checkpoint — Then Airlines Hand It To You On The Plane

You can’t bring this knife through security and bring it on an airplane – but you can be given this knife on an airplane. Make it make sense! This passenger is wrong to blame this on TSA, though, let alone take it out on the front line screener who isn’t expected to ponder the existential nature of the role.

Blame Congress – and the various interest groups that stand in the way of risk-based security that would keep us safer (and be less inconvenient to passengers at the same time).

My airline meal included this knife. I want to steal it and leave it in my carry-on.

The next time I fly, I will explain this to the TSA guy, so he will feel the full philosophical absurdity of his job. pic.twitter.com/iDDSNukLtc

— Dr. Insensitive Jerk (@DrInsensitive) April 12, 2026

Knives that are round-bladed, blunt-edged, and without serration actually are allowed.

The knife in this photo isn’t allowed in a passenger carry-on, but can be used on an airplane. But it’s only just barely banned.

Passengers are permitted to bring true butter knives through security. This one has minor serration, so it’s not allowed. And the TSA screener is given the discretion to make the determination, even if you brought the knife off the aircraft that won’t matter.

It’s not TSA that’s doing this! It’s Congress! By law, TSA is not permitted to “amend[..] the interpretive rule to authorize any knife to be permitted in an airport sterile area or in the aircraft cabin” other than “plastic or round-bladed butter knives.”

TSA actually intended to allow small knives a decade ago – arguing that they should be focusing on real threats, and these were a distraction, but there was an uproar over it. They dropped the proposal and then Congress banned them from considering it again in the future.

Nonetheless the point in the tweet is true:

• passengers cannot carry serrated knives through TSA checkpoints
  
• authorized airport, airline, and concession staff and businesses can bring them in
  
• and, in some cases, even make them available to customers – who might pocket them and bring on a plane .. or they might be given the knife on a plane.

As I wrote 23 years ago, though, “the point of not allowing an object through security was to prevent it from getting onto the plane.” Weird, huh. Then again even metal butter knives used to be banned on board, yet metal forks – you can bend back the tines! – were just fine.

Meanwhile, airport restaurants often have real knives at least in the kitchen, and the security is taken pretty seriously. Procedures at each airport will differ, but:

• Denver requires knives and similar prohibited items to be inventoried and logged three times a day, kept secured when not assigned, kept inaccessible to passengers, photographed, and listed on an approved master inventory.

• Ontario requires concessionaires to show how prohibited items are secured and to audit approved inventories.

• New Orleans requires recording of each knife’s location and whether it is tethered to the wall, which is one default way to control access.

• San Francisco requires concessions to coordinate with airport security to bring knives into the restricted area, show how they are secured, and audit their inventories.

So a round-bladed butter knife is fine, while a very similar small table knife with serrations is not (even if it’s given to you on a plane). Scissors under 4 inches from the pivot can go in your carry-on, while knives with blades even smaller than that can’t. (“(T)aking (S)cissors (A)way never made any sense, of course.)

Tools 7-inches or shorter can be in your carry-on, and TSA even lists lock picks as fine. A tiny pocketknife is not ok.