There’s not much to a flat bar, but like a nail puller they are occasionally really handy. For instance, if you need to make a small adjustment when installing a door, a flat bar can be put under one side and stepped on to get the door exactly square. This also frees up your hands to secure the door with your impact driver. It's also used when installing the flooring to make sure your last row or boards is tight.
We tested 3 different flat bars and found the Estwing 15-Inch Forged Half-Round Handy Bar to be the best. It’s the only flat bar with a curved shaft which reduces flexing. That extra rigidity is nice when you don’t have a lot of room to move the tool. We also have a few of the Vaughan Original SuperBar’s that we use, which are also great, although not as rigid as the Estwing.