With the increasing use of technology, files and rasps are not appreciated as much by the modern woodworker and are considered as tools to be used only for rough work. These are however, excellent tools that woodworkers can use for fine woodwork as well.
The essential difference between files, rasps and rifflers
How are files and rasps different? Files have rows of parallel sharp ridges and can be single cut or double cut. On single cut files, the teeth are at 65-85 degrees to the center line. On double cut files, the teeth on the first row are at 40 – 45 degrees to the center line and the second row teeth are at 70 -80 degrees to the center line.
The teeth are angled so that a slicing cut can be achieved and the angle is set according to the hardness of the metal the file is intended for. Double cut files give woodworking objects a rougher finish than single cut files. As a general rule, the fineness of the teeth increases with the hardness of the metal.
The angle of the face of a file tooth slopes back rather than forward so that it is less likely to jam metal filings into the gullet. This is called negative rake. In practical terms the negative rake will cause the file to bounce over the surface of the woodworking object rather than cut it, if the file is pushed too quickly.
Rasps have individual teeth that are formed by driving a punch into the surface of heat softened steel. The raised flap that results becomes the tooth and then the rasp is case hardened.
Rifflers, the third important tool enable woodworkers to shape details of furniture and are useful for carving. Rifflers can be rasp cut or file cut and have a different grade of cut at each end of the steel. Some woodworkers who do a lot of carving proclaim rifflers to have their most used hand tool.
Which tool is best for woodworkers
All woodworkers have different requirements and all three tools have a place in a woodworker's toolkit. A 10 "half round file is suitable for use on metal and also works well to shift wood without choking. It requires constant clearing when working wood but can be used to improve a rough shaped surface.
For a smoother finish woodworkers can consider using mill files. These are single cut and are good for tasks such as truing the edges of a cabinet scraper. An even finer finish can be achieved by drawing filing which is using the files at right angles to the cutting stroke.
Many woodworkers do not realize that the teeth of rasps are randomly distributed, but machine cut rasps have regular rows of teeth which will leave furrows as each tooth follows directly in the track of those before it. Rasps that appear as crude tools do so because they have been badly made or because too coarse a cut was being used.
Using Rasps and Files
Rasps and files by their very design are meant to cut only on the push stroke. Dragging them back over the woodwork piece causes the tools to wear out much faster and result in a poor finish on the job.
While working with boards such as MDF, it is best to use cheap tools which can be binned once the work is over as they will wear out files and rasps much faster. Quality tools should be used with natural wood for long lasting results.
Relying on a good selection of rasps and files can enhance the pleasure of woodworkers and are a great help wherever to smooth out a tear on a drill bit shaft, sharpen screwdrivers, shape wood or transform a tornened surface into a formed one. These are just some reasons why a woodworker's tool chest is never complete without these tools.
Source by Tamara Korremans