KnKut Car Reamers are made of high-speed steel and are specially designed for TRUING, ALIGNING, DE-BURRING and ENLARGING holes in structural steel members, automotive maintenance and fabrication. The short overall length makes it very useful in cramped quarters with any 1/2", 3 jaw power tool. These reamers perform excellent in various types of metals including mild and surface hardened steel, 4140 steel and cast iron. The built in collar prevents over penetration while the LEFT HAND FAST SPIRAL, RIGHT HAND CUT is developed for high-speed use. Grab-free use is even possible with larger diameters.