A sling blade or kaiser blade is a hand tool comprising a heavy, hooked steel blade at the end of a long (around 100-centimetre (40 in)) handle that is usually made of wood. The blade is double-edged, and both sides are usually kept sharp. The tool is used to cut brush, briar, and undergrowth.[1] Its use is somewhat similar to that of an axe, and it is sometimes viewed as a type of axe. Other common names for the tool are bush knife, ditch bank blade, briar axe, and surveyor's brush axe. On the East Coast of the United States some farmers call it a bush axe. The Plover, Wisconsin dialect refers to it as a ditch witch. Also historically used as a wildland firefighting tool to cut fireline, known as a brush hook. It is also sometimes referred to as a bush hook in south eastern North Carolina. Its use in wildland fire has been substantially superseded by the chainsaw.
It generally has a 12-inch (30 cm) to 16-inch (41 cm) curved blade and a 36-inch (91 cm) to 48-inch (120 cm) handle. It is commonly used by surveying crews and firefighters to clear out heavy undergrowth from trails, as well as by homeowners and gardeners to clear thick brush.[2]