The file is made of carbon tool steel T12 or T13 after heat treatment, and then the working part is quenched. It is a small production tool. It is a hand tool for filing the workpiece. It is used for micro processing of metal, wood, leather and other surface layers.
The earliest records of files in the world come from Greek documents. According to records, the Greek Crete civilization invented the bronze file around 2000 BC. The ancient Egyptians invented the earliest copper file in 1300 BC, and the iron file was invented around 700 BC. It is recorded in the West that around 1100 AD, the ancient Romans made files using carburizing heat treatment technology. However, it is believed that carburizing technology has been widely used in file processing in ancient China during the Qin and Han Dynasties around 200 BC. A file unearthed from the Han Tomb in Mancheng (113 BC) proves this statement-"Slim shape, broken at one end. Nearly half of the single side is chopped with horizontal flat files, and there are six teeth in 1 cm." . Similar to the "horse tooth file" of the early 21st century, it belongs to the type of wooden file. The length of the remaining part is 20.4 cm, the width is 1 cm, and the thickness is 0.3-0.5 cm."
The application of the file is very early, and the oldest file found is the bronze file of Egypt around 1500 BC.
Modern files are generally made of carbon steel by rolling, forging, annealing, grinding, cutting teeth and quenching. The file is made of t12 steel, which has a hardness of 62~64 after surface quenching.
There are many varieties of burrs .
①According to the purpose, there are:
Ordinary fitter's burrs, used for general filing processing;
Wooden burrs, used for filing soft materials such as wood and leather;
Plastic burrs (assorted files), used for filing small and fine metal parts. There are many files with various cross-sectional shapes to form a set;
Sharpening the burrs for woodworking saws;
Special burrs, such as flat and arch shaped burrs (special files) for repairing special shapes, are available in straight and curved shapes.
②burrs are classified into Flat Files, Square burrs, Half Round burrs, Round burrs, Triangular burrs, Diamond Files, Knife burrs, etc. according to their cross-sectional shapes. Flat burrs are used to burrs flat surfaces, external circular surfaces and convex arc surfaces; square burrs are used to file square holes, rectangular holes and narrow flat surfaces; triangular burrs are used to burrs internal angles, triangular holes and flat surfaces; semicircular burrs are used to file concave arc surfaces And flat surfaces; round burrs are used to burrs round holes, concave arcs and ellipses with smaller radius.
③burrs are divided into single-grain burrs and double-grain burrs according to the file pattern. The teeth of the single-grain burrs are inclined at an angle to the axis, which is suitable for processing soft non-ferrous metals; the main and secondary burrs of the double-grain burrs are arranged in a crossed arrangement, which is used for processing steel and non-ferrous metals. It can divide wide filings into many small sections, making filing more brisk.
④burrs are divided into No. Ⅰ ~ Ⅴ according to the number of main burrs lines per 10 mm length, among which No. Ⅰ is Bastard for coarse tooth burrs, No. Ⅱ is for middle tooth burrs Second, No. Ⅲ is smooth for fine tooth burrs, No. Ⅳ and No. Ⅴ It is a polished burrs, which is used for roughing and finishing respectively. The diamond burrs has no burrs pattern, but a layer of diamond powder is electroplated on the surface of the burrs to burrs hardened metal.
