🔪 Knife sharpener

No. Pull-through sharpeners contain sharp carbide or ceramic elements and are prohibited in carry-on. Check them.

A honing steel (the long metal rod used to straighten knife edges) is prohibited in carry-on — it exceeds the length and could be used as a weapon. Check it.

Whetstones (flat sharpening stones) are less likely to be flagged than pull-through sharpeners, but screeners have discretion and no aviation authority explicitly lists them as permitted carry-on. The safest approach is to pack all knife-sharpening equipment in checked baggage to avoid any risk of confiscation.