as per the TSA website: http://www.tsa.gov/interweb/assetlib...ited_Facts.doc

These items below can be in your checked and carry-on luggage:

Tools - (seven inches or less in length)
Screwdrivers - (seven inches or less in length)
Wrenches and Pliers - (seven inches or less in length)

These items below must be in your checked luggage:

Axes and Hatchet
Cattle Prods
Crowbars
Hammers
Drills and drill bits - (including cordless portable power drills)
Saws - (including cordless portable power saws)
Tools - (greater than seven inches in length)


Note Any sharp objects in checked baggage should be sheathed or securely wrapped to prevent injury to baggage handlers and security screeners.