Rasps are designed to shape and smooth out the surface of materials, they are essentially a metal bar with triangular shaped teeth designed to remove small amounts of material through abrasion much like a file.

This triangular shaped tooth pattern allows rasps to be used on softer materials and are most used with wood, plastics and even horses' hooves in place of a file.

Types of Rasp

Rasps come in various shapes and sizes and are either machine stitched or hand stitched. Machine stitched rasps have all their teeth in a uniform pattern of rows and carve grooves rather than smoothing out surfaces. Hand stitched rasps are less uniform in their teeth arrangement and work better at smoothing out surfaces.

Within these two types of rasps there are variations suitable for all manner of applications. Below we have listed some of the most common types.

Cabinet rasps - The most common type of rasps used primarily in woodworking. Either half round or with one flattened edge, they're a good general-purpose rasp.

Modeller's rasps - A smaller, narrower version of the cabinet rasp, these rasps are better suited to working in detail.

Cranked neck rasps - Featuring a slim cut face and tang and handle bent to one side, cranked neck rasps are great for use in confined spaces.

Round rasps - with a cylindrical blade round rasps are ideal for smoothing out curves and for filing spiral patterns into wood.

Square and knife rasps - Much like their file namesakes, they are used in similar applications but are specifically designed for use on wooden surfaces.

Needle rasps - Needle rasps are smaller, narrow rasps used for precision shaping applications. They are mostly used in the making of musical instruments.


What type of rasp do I need?
This will depend on the application, for example intricate working will require either a modeller or a needle rasp as their smaller size lends them to detailed applications. Working highly curved edges will often require the use of a round rasp as the cylindrical blade is more adept as producing a smoother finish.

How coarse are rasps?
Rasps vary in coarseness depending on their teeth, in short, the larger the number of teeth per row the finer the grade, this is usually ranked in three different ways.
The American system follows that of files i.e., coarse, bastard, second cut, smooth or dead smooth. Another way rasps are categorised is to count the number of teeth. Finally, the grading system from 1-15, 1 being the coarsest designed for industrial work only, to grade 15 that has lots of very small teeth to produce a fine finish.