Guide written by:
Sebastian, self-taught DIY-er, Exeter
Finishing tool par excellence, the rasp is to the wood what the file to the metal. A surplus of material? No matter, with a few strokes your problem will be solved. Depending on their teeth or ridges, rasps and files can used to trim or finish a variety of materials.
How to choose a rasp
A rasp is a long, often tapered bar of steel with either flat or rounded edges and rows of ridges or teeth along its surface for removing material. Depending on the shape, arrangement, and intensity of these ridges, the rasp may be suited to specific materials and to removing more or less material with each stroke.
Types of teeth
Fine: For producing an impeccable finish. Fine teeth can also be found on rasps and files for working with sturdier materials such as hard woods and metals.
Average: For everyday use. Rasps with average size teeth are a good ‘jack-of-all-trades’ to have around.
Coarse: For removing a lot of material quickly. These rasps make sort work of wood and other soft materials but should not be used for finishing as they usually leave marks in the material.
Once your chosen the teeth you need, all that remains is to select the profile.
Flat: The cross-section of these rasps is flat on all four sides. They are best suited to work on flat surfaces.
Round: Also called a rat tail. Round rasps are most commonly used to finish notches but work well for any round or irregular shape.
Half-round: If you are unsure of the work that awaits you, a half-round rasp can be a good compromise. If you have to buy one rasp for all work, look for a half-round with average size teeth. It should be able to meet most of your needs
For the handle, you will usually have the choice between wood and synthetic material. As with most handles, wood offers greater comfort while synthetic handles come in more ergonomic shapes. There is no right or wrong choice, just look for the one that you find more comfortable.
The rasp is mainly used on wood. It is a common part of a joiner’s tools, a set of hand tools such as a planer.
How to choose a file
Unlike a rasp, a file does not have teeth, but ridges. As with the teeth of a rasp, a files ridges remove more or less material according to their spacing and their arrangement. A file is mainly used on metal.
Sanding file: With 1 mm ridges, your file will be very aggressive and remove a lot of material.
Semi-soft or medium file: From 0.3 to 0.5 mm, these are more like all-purpose files for everyday use.
Fine file: ≤ 0.2 mm, for finishing work or for especially delicate materials.
After choosing the ridges you need, all that remains is to determine the profile.
Dish: Used for smoothing protrusions or imperfections in flat surfaces.
Round: Also known as a rat tail, for filing notches or any rounded shape. These files are commonly used for sharpening chainsaw chains.
Half-round: These files are a versatile choice. They lend themselves to many different types of work.
Square, Triangular, or Diamond: To adjust an angle, notch, or groove. These shapes are often used for sharpening saw blades.
As with the rasps, the handle is most commonly found in wood or synthetic material. Choose the one that yo find most comfortable or that suites you best.
Files and rasp can both be bought independently of a handle. These models end in a short, narrow metal tang.
For greater versatility, choose a file or rasp with different kinds of teeth or ridges on each side, or if it makes sense for you to invest a little more money pick individual files for different tasks and materials and build a complete set.
Remember to adapt the teeth or ridges of your rasp or file to your work. Any material you remove is lost material. Make sure you’ve done it properly.
For DIY enthusiasts interested in knowing how to choose the accessories related to rasps and files, follow the advice of our editors and discover their Guides:
- How to choose your carpenter joiner tools
- How to choose your hand planer
- How to choose your circular saw
- How to choose your circular saw blade
- How to choose your chainsaw
- How to care for your chainsaw
- How to choose your hacksaw
- How to choose your sander
- How to choose your wood saw
- How to choose your coping saw
- How to choose your sanding sheet and abrasive paper
- How to choose your wooden router
- How to choose your workshop sander
And to work safely:
Guide written by:
Sebastian, self-taught DIY-er, Exeter, 198 guides
Redo a roof with wooden beams? Check.Advise Mister everybody in the DIY shop? Check.Redo the bathroom plumbing? Check.Fit together, build the walls, paint a partition, throw my hammer in a rage thinking that it will fix the problem? Check. The DIY motto ? Learning is better than delegating… well, it's also a question about your wallet! The satisfaction? The beer at the end of the job! What do the best have in common? The influence of Gyro Gearloose, Mac Gyver and Carol Smiley depending on your generation, a good dose of curiosity, a average hand-eye coordination and a taste for risks… and if it doesn't work, try again! Advise you? I'll do my best!