Engineering files also known as hand files are a type of hand tool used to smooth, deburr and shape a range of materials including metals and wood whilst removing any unwanted material after cutting or sharpening. Files are shaped rectangular, square, triangular or round cross-section and include teeth cut into at least one of its sides with three common grades including coarse, bastard, second cut and smooth. Engineers files can also be used with a filehandle to make its use more ergonomic.
These files are normally held in both hands when using. The file will be placed flat onto the surface that you will be smoothing and then pushed forward, cutting on the forward stroke. This action will then be repeated until it has removed the material you don't want and is smooth.
The cut refers to how the pattern of the teeth are cut into the working face of the file. Engineers files are available with various types of cut, depending on the type of application required. The most common types are single cut, bastard cut, double cut and rasp. Single cut files are commonly used to smooth and deburr with precision whereas a double cut is used to remove stock material quickly and efficiently.