I copied the below list from the TSA site. Sorry that it's a little jumbled, but as it reads, nail clippers are permitted in both carry-on and checked luggage.
We're packing a small pair clippers in our carry-on. The clippers had a small file that I snapped off.
The cable ties that I'm using are thin (thin but tough!), making it easy for the small clippers to cut.
Can I take it? Carry-on Checked
Personal Items
Cigar Cutters Yes Yes
Corkscrews Yes Yes
Cuticle Cutters Yes Yes
Eyeglass Repair Tools (including screwdrivers) Yes Yes
Eyelash Curlers Yes Yes
Knitting and Crochet Needles Yes Yes
Knives, round-bladed butter or plastic Yes 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 No 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