The body of a pocket rasp also serves as the handle, and is made of plastic or cast metal. Many pocket rasps will channel or collect the plaster shavings and dust within the body or handle.
Blade
The blade is the perforated metal plate on the underside of the rasp that often resembles a cheese grater.
Teeth
Some blades with coarse teeth (larger perforations in the blade) will remove more material than others, decreasing the time it takes to trim small amounts off the edge of plasterboard. Blades with fine teeth that remove less material will give a smoother final finish to the edge of the plasterboard.
Screw
The screw is used to secure and provide tension to the blade of the rasp. Screws will only be found on rasps that have a replaceable blade. Turning the screw anti-clockwise will slacken it and remove tension from the blade, allowing it to be removed, while turning the screw clockwise puts tension on the blade and holds it in place.
The screw on some models is a plastic thumb screw that enables you to turn it and alter the tension of the blade without the need for a screwdriver or other additional tools.
