File size ruler?
The specification of locksmith file refers to the length of file body.

The specification of special-shaped file and plastic file refers to the full length of the file.

The assembler files the body (the distance from the file tip to the file shoulder). In terms of length, there are several specifications: 100 ~ 150 mm, 200-300mm and 350-450 mm

The full length of special-shaped files and plastic files are specifications. The basic dimensions of a file mainly include width and thickness. For circular files, diameter.

Main parameters of file mode file

(1), locksmith file

File number-parameter indicating the thickness of file teeth. According to the number of main gears within the axial length of 10mm, there are five types, namely 1, 2, 3, 4 and 5. The smaller the file number, the thicker the file teeth.

(2), special-shaped file

The document number-* * * is divided into ten types: 00, 0, 1, 2...8.

The file is made of carbon tool steel T 12 or T 13 after heat treatment, and then the working part is quenched.

A hand tool with many fine teeth on the surface, used to file workpieces. Files were used very early, and the oldest file found was a bronze file made in Egypt around BC 1500. Modern files are generally made of carbon steel through rolling, forging, annealing, grinding, tooth cutting and quenching.