When I fly, I use the blunt-nosed ones by Fiskars found at Walmart in the school section. They are allowed by TSA on planes.
Here is the scoop:
Personal ItemsItem Type Carry-on Bags Checked Bags
Baby teethers with gel or liquid inside No Yes
Children's toys with gel inside No Yes
Cigar Cutters Yes Yes
Corkscrews Yes Yes
Cuticle Cutters Yes Yes
Eyeglass Repair Tools (including screwdrivers) Yes Yes
Eyelash Curlers Yes Yes
Gel candles No Yes
Gel shoe inserts No Yes
Knitting and Crochet Needles Yes Yes
Knives - prohibited as carry-on except for plastic or round bladed butter knives. No Yes
Nail Clippers Yes Yes
Nail Files Yes Yes
Personal care or toiletries with aerosols, in limited quantities (such as hairsprays, deodorants) Yes Yes
Safety Razors (including disposable razors) Yes Yes
Scissors - plastic or metal with blunt tips Yes Yes
Scissors - metal with pointed tips and blades shorter than four inches in length Yes Yes
Toy Transformer Robots Yes Yes
Toy Weapons (if not realistic replicas) Yes Yes
Tweezers Yes Yes
Umbrellas (allowed in carry-on baggage once they have been inspected to ensure that prohibited items are not concealed) Yes Yes
Walking Canes (allowed in carry-on baggage once they have been inspected to ensure that prohibited items are not concealed) Yes Yes
Sharp Objects Item Type Carry-on Bags Checked Bags
Box Cutters No Yes
Ice Axes/Ice Picks No Yes
Knives - prohibited as carry-on except for plastic or round bladed butter knives. No Yes
Meat Cleavers No Yes
Razor-Type Blades, such as box cutters, utility knives, razor blades not in a cartridge, but excluding safety razors No Yes
Sabers No Yes
Scissors - metal with pointed tips and blades longer than four inches No Yes
Swords No Yes
Note: Any sharp objects in checked baggage should be sheathed or securely wrapped to prevent injury to baggage handlers and inspectors
As you can see, if the blade is longer than four inches, it is not allowed on carry-on luggage. Shrter than that and it is.