It seems like the first tongs that people try to buy when starting out is flat tongs. I suppose they are assuming flat tongs are for flat stock, and while they're correct, its not that simple.
A better name for flat tongs is Blank Bit tongs. Blank because they have not been formed into a shape that really holds anything...yet. Although they can grab onto flat stock, they require a temedous amount of force to keep the stock from slipping. The kind of force needed will make your hand cramp, unless you enjoy chasing the stock around your anvil and floor below. Using tongs like this is dangerous. I hear storries of partially forged knives flying around. I once heard that, while using flat tongs, a blade flew up and sliced the chin of a novice bladesmith. Although I never saw the damage, i can definietely imagine it happening.
Lets add another wrench into the mix. There are Flat Open Tongs and Flat Closed Tongs. Self-explanatory, right?
Not so much as it begs