Are you looking for some tool to take out that rusting, stripped and broken screw from your kid's study table? If yes, Dayton Screw Extractor Set Part No SE- 600 is a quick and easy way to remove broken screws, pipes, bolts & studs. The set comes in the sizes of (inches) 1/8, 1/4, 5/16, 7/16, 9/16, 3/4 to meet different needs perfectly. It is made of Chrome Vanadium Steel. These flutes are designed to embed themselves deeper into the metal as you turn the tool. The extractor's grip increases, material Chrome Vanadium Steel coated surface can reduce friction and overheat when drilling through metal for longer lifetime. These Screw Extractor Set bits work excellently in making a smooth, clean, and a perfectly round hole.longer lifetime. These Screw Extractor Set bits work excellently in making a smooth, clean and perfectly round hole.