A kaiser blade or sling blade is a heavy, hooked, steel blade at the end of a 40-inch (100 cm) handle that is usually made of hickory wood.
The blade is double-edged, and both sides are usually kept sharp. It is used to cut brush, briar, and undergrowth.
Other common names for this tool are 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.
In the movie Sling Blade, main character Karl Childers (portrayed by Billy Bob Thornton) recounts an incident from his childhood in which he killed his mother and her paramour with this tool. Childers describes it as, "some folks call it a sling blade, I call it a kaiser blade. It's just a long handle, kind of like an axe handle. With a long blade on it shaped kinda like a bannaner. Mhm. Sharp on one edge, and dull on the other. Mhm. It's what the highway boys use to cut down weeds and whatnot."
In the novel Red Rising, Darrow acquires a sling blade during a training game. After breaking the rules of the game and attacking the proctors, he becomes known as "The Reaper" with the sling blade as his sigil.