Different Types of Files and their Specific Use
The file has existed since practically the pre-industrial era; it is an extremely simple manual tool but indispensable in the toolbox of almost anyone. Its primary use is roughing metal parts, wood, and to a lesser extent, plastic. It is a ubiquitous tool, with dozens of different models.
We will focus on the different types used in workshops and factories, the various existing profiles and their graduation according to the number of teeth. We will also see the difference between a file, a rasp, and a scraper.
Files: Definition and Types
In Spanish we commonly use the word lime to refer to a set of manual tools for removing chips; among them, we have the files themselves, rasps and scrapers.
They are manual tools -as we have already seen- that allow the roughing of metals in general as long as their hardness is not excessive. There are many different models, and they are used in various industries: from metallurgy to carpentry, construction, medicine, and personal care.
The files used in construction and metal-mechanics are also the most common in the shops of the branch: the parallel flat ones, the half cane, and the round ones.
The construction of a file is simple: one starts from a steel strip to which successive angled millings are applied; first in a positive angle and then in blotting lines to the first ones.
Files can be sorted according to the number of teeth per unit area; the standard ranges from 18 to 1200 teeth per cm².
They are similar to files but are used for softer materials than metals, such as wood and some plastics that could fill the files.
The main difference is in the chopping: the teeth of the rasps are large, and the geometry is different. They are arranged in horizontal and parallel bands to each other, which allows the wood to be attacked more easily, without allowing sawdust particles to be trapped between the teeth.
As with files, there are different geometries: flat, round, triangular, square and half-round.
This tool can be acquired in specialized houses, or it can be made from an old file. Unlike the rasp and the lime, the scraper uses the tip to achieve the removal of chips. Its work is similar to that of a gouge: through the removal of chips is achieved the smoothing of metal surfaces (which are then controlled with an adjustment marble and Prussian blue).
The way to use this tool is very simple: you paint the surface of marble of adjustment, and you lean on it the surface to level. When it is removed, the Prussian blue will indicate the points to be lowered with the squeegee. The task is repeated until the surface is reasonably flat. This is useful when the part is small, and a grinding machine is not available.
Files in general (and here we are talking about rasps, rasps, and files) are not only flat; there is variety in the profile that the cut faces acquire.
Flat files are used for deburring, roughing and adjustment on flat surfaces. The same applies to half-round files which are also used to adjust concave surfaces.
Files with an almond profile are used exclusively for concave surfaces. The round ones are used to adjust holes.
The triangular is used to mark a groove before sawing; it is also used in the adjustment of flat interior surfaces where a flat file does not have access. The diamond file is used to adjust V-grooves.
Finally, the blade and diamond files are used in tooling where it is necessary to adjust sharp angle slots.
Correct Use of the File
The file should always be used with both hands. Take the handle with the right grip and use the other to take the tip. With the thumb back and the remaining four fingers leaning forward, only on the face that is not in contact with the material.
Any other position of the fingers presents the risk of pinching or cutting.
Cleaning the Files
There is a unique tool for cleaning files. It is called a brush, and it is merely a brush with fine metal bristles, placed on one of its faces.
When the brush is passed along the grooves of the file, all the material that is trapped between the teeth is detached.