A broad axe is an axe with an extremely broad blade and a very heavy head. This design is intended for use in squaring timbers. Using a broad axe requires a great deal of skill and physical strength, and the necessary skills are growing uncommon, due to the proliferation of mechanized logging equipment which does the same job. It is still sometimes possible to purchase broad axes from logging supply companies and hardware stores.
A typical broad axe has two distinct sides. On one side, the blade of the axe is flat, making it easy to create a smooth edge. On the other, the blade is beveled, allowing the user to wedge it into the wood. When squaring timber, the flat side is faced against the side of the timber, while the bevel side faces the scrap edge, allowing the user to create a smooth edge with one stroke. Because broad axes have two distinct sides, there are right and left hand versions with handles to match.
The most classical use of a broad axe was for creating square timbers such as those used to brace homes and make railroad ties. Once a tree had been felled, a lightweight axe was used to lightly score the timber in a straight line, creating a mark to follow with a broad axe. The user stood on the log to wield the broad axe, and brought it down in powerful blows which were designed to split the timber along the line, creating a squared edge. Once one edge had been made, the log could be flipped to begin on the next edge.
If you ever enter a structure which was constructed in the era when logging was accomplished by hand, you will probably be able to see the strokes of a broad axe on the timbers. Someone who was experienced with the broad axe and in peak physical condition could churn out scores of timbers a day, ensuring the the production line was not clogged by timber waiting to be processed.
In addition to being used to create square timber, a broad axe can also be used to make octagonal timbers, such as those classically used as the masts for ships. A skilled user could also utilize a broad axe to make flooring planks. Some logging competitions still include a broad axe division for loggers to showcase their skills with this classic logging tool.