What a rasp is
A rasp is a hand tool for removing wood quickly. It has a steel body covered in individual, raised teeth, which are often called stitches. You push the rasp across the surface, and the teeth tear away small amounts of material. Rasps are commonly used to shape curves, round off edges and fit parts before smoothing with finer tools.
Another word for a rasp is sometimes “coarse file”, though the two tools differ, as described below. A rasp is a shaping tool. It is used on wood and other soft materials, and some types are designed for hooves or soft stone.
Rasp versus file
What is the difference between a wood file and a rasp? In general:
- A rasp has separate, individual teeth that remove material quickly and leave a rough surface.
- A file has fine ridges, usually cut in lines across the face, that remove less material and leave a smoother result.
Files are also commonly used on metal, while rasps are mostly used on wood. In practice, woodworkers often use a rasp first and then a file or scraper to refine the surface. If you are looking for the three common types of hand files, flat, half-round and round are the usual shapes, and these shapes also apply to rasps.
Types of rasps by shape
Flat rasp
A flat rasp has a flat cross-section. It is used for flattening surfaces, working straight edges, and shaping outside curves.
Half-round rasp
A half-round rasp has one flat side and one curved side. This makes it a versatile choice, and many woodworkers start with this shape. The flat side handles flat areas, and the curved side works concave curves.
Round rasp
A round rasp, sometimes called a rat-tail rasp, has a circular cross-section. It enlarges holes and shapes tight inside curves. The thickness varies.
Other shapes
Less common shapes include triangular rasps, and shapes used in specialized work such as carving and chairmaking.
Types of rasps by tooth pattern
- Machine-cut rasps have teeth that are made in a regular pattern. They are generally more affordable and may leave a more visible pattern of marks.
- Hand-stitched rasps have teeth punched individually, in a more random arrangement. These are generally more expensive. Many users find that they leave a smoother surface, because the teeth do not line up in rows.
- Cabinet rasps are a style with a particular tooth layout, designed for general furniture work and finishing.
- Patternmaker’s rasps are finer tools sold for detailed shaping and finishing.
- Planer-style or surface-forming tools use replaceable blades and are available in many hardware stores. They are quick for shaping, though they work differently from a classic rasp.
The names vary by manufacturer, so read the description to understand the style.
Grades
Rasps come in grades that describe how coarse the teeth are, ranging from coarse for fast removal, through medium, to fine for more refined work. A common approach is to start coarse to remove the bulk of the material and then move to finer grades. Different manufacturers use different grade names, so grades are not perfectly consistent across brands.
Specialty rasps
Some rasps are designed for specific trades, such as farrier rasps for hoof work. Using them for woodworking is possible, but they may be larger and coarser than needed.
Using a rasp
- Secure the workpiece in a vise or with clamps.
- Use a handle to improve control. Many rasps have a tang that fits into a wooden handle.
- Push the rasp forward with light pressure, and lift it on the return stroke, as rasps typically cut on the push.
- Work at a slight angle across the grain for a quick removal, and along the grain for a smoother finish.
- Check your progress often, since rasps can remove material quickly.
- Refine the surface with finer tools afterward. If a rasp is part of a project that needs chisel work, see our guide to chisel types.
Cleaning and care
Wood dust and resin can clog the teeth. A stiff brush, brushed along the lines of the teeth, helps to clean them. Store rasps so that they do not knock against other metal tools, since teeth can chip. Rasps typically cannot be sharpened in the way chisels can, so avoid dropping them or using them on metal. Do not strike a rasp with a hammer, since the hardened teeth and body can chip or break.
Frequently asked questions
What are three common types of hand files used in a workshop?
Flat, half-round and round are three common shapes.
What is another word for rasp?
It is sometimes called a coarse file, though a rasp has individual teeth rather than ridges.
What is the difference between a wood file and a rasp?
A rasp removes wood quickly with individual teeth. A file removes less and leaves a smoother finish.
What type of tool is a rasp?
A hand tool for shaping, usually of wood.