These Blacksmiths Flatter tools have flat faces with sharp or rounded edges according to requirements and are placed on the work and struck with the hammer. The flatter is a good finishing tool and should be used only to impart a good finish to flat surfaces These can also be used for final work on shoulders and offsets, should not be used as a replacement for a Set Hammer
Due to the vibrations that are transmitted through the handle these were originally not handled tightly. Loose handles, spokes or wire wrapped through the eye was common. Just strong enough to place on the surface and would be reset or positioned after every blow