Lyn-Tron's Washer Thumb Screws are designed to be installed by hand rather than by hand tools or power tools. The high-quality knurl provides a non-slip surface to grip onto. In addition, the washer face provides a decorative appearance, but also adds clearance between the head and mating part making these screws easy to unscrew compared to a plain thumb screw. The round shape provide a nice finished look. Brass is corrosion resistant, nonmagnetic, and easily machinable. Base metal is yellow, but many plating options are available when different colors are required.