Files

Files: The most widely used hand tool to be found in an engineering workshop is called ‘file’. It is used to cut, smooth, or fit metal parts. It cuts all metals except hardened steel. Steel files are made from high carbon steel (1.0 to 1.25% carbon) and may be through hardened or case hardened.

1. Flat file,  2. Hand file,  3. Square file,  4. Pillar file 5. Round file 6. Triangular file 7. Half round files 8. Knife-edge files, 9. Neddle file

Part of files:

Tang: - it is the pointed part which fitted into the handle.

Heel: It is next to the handle.

Edge: The safe edge or side of a file is that which has number teeth.

Point: It is the end opposite the tang.

Length of file:- it is the distance from the point to the heel without the tang.

Size of files: The distance from the point to the heel without the tang. Files for fine work are usually from 100 to 200 mm and those for heavier work from 200 to 450 mm in length. 

Cut of teeth: Cut of file is divided into two groups they are:-

1. Single cut file: In the teeth are cut parallel to other across the files at an angle of about 60° degree to the centre line of the file.

2. Double cut file: Double cut file have two sets of teeth the over cut teeth being cut at about 60° degree and the up-cut at 75 to 80° degree to the centre line.

Use a double-cut file to file brass, bronze, copper, and tin. These tough metals should be filed with a double-cut file as they are strong enough to withstand the metal and/or alloy. Rasp-cut files can be used for wood as well as lead and aluminum. This file has a series of individual teeth and produces a rough cut.

Type of files: The shape of a file is its general outline and cross-section. Files are made in hundred f shape. Most commonly used shapes.

1. Flat file: This is tapered in width and thickness and one of the most commonly used files for general work. They are always double –cut on the faces and single cut on the edges.

2. Hand file: This is parallel in its width and tapered in thickness‘. A hand files is used for finishing flat surface. They are always double –cut.

3. Square file: This is square in cross section, double-cut and tapered towards the point. This is used for filling square corners, enlarging square or rectangular openings as splices and keyways.

4. Pillar file: Pillar file are double cut, narrow and of rectangular section.

5. Round file: They are round in cross section and usually tapered .Round file are used for filing curved surfaces and enlarging round holes and forcing files. They may be single cut or double cut.  

6. Triangular file: Three square or triangular file is tapered, double cut and the shape is that of an equilateral triangle. They are used for rectangular cuts and filing corers less than 90 degree.

7. Half round file: This is tapered double cut and its cross section is not a half circle but only about one-third  of a circle. This file is used for round cuts and filing curved surfaces.

8. Knife-edge files: This is shaped like a knife, tapered in width and thickness and double cut. They are used filing narrow slots, notches and grooves.

9. Diamond Needle Files: These files are available in various sections and are manufactured from high quality steel uniformly electroplated with diamond particles. Normally used by hand. A plastic handle is available. They can also be used in N.S.K. and Diprofil reciprocating Filing machines.

Grades 

There are four different grades for American Pattern Files:

1. Coarse Cut,

2. Bastard Cut,

3. Second Cut, 

4. Smooth Cut. 

They range in that order from fewest to most teeth per inch.

Method of filling: There are three type of filing:

Cross-filing: In ‘cross-filing’ the file strokes run alternately from the right and from the right to the left. This is the commonest from of filing and the one used for general shaping. In this method the possibility of rounding is minimized and the score marks made in the work by the file teeth are crises-crossed. So that maximum amount of metal is removed. The aim in cross-filing is always to move the whole of the file surface a cross the whole of the work surface in one stroke.

Draw- filing: In draw filing the handle of the file is not held. Instead, both bands are placed to close together on the blade. The file is placed at right angles across the work while the handle and especially the thumbs grip. The file and move it up and down the length of the metal. It does not more much material.

Straight- filing: In straight filing the file is pressed forward. Approximately at night angles to the length of the work on the back stroke, the file should be lifted clear of the work in order not to blunt the teeth straight filing is specially useful on long and narrow piece of work whose is less than that of the file.

Care of file: File are very brittle and should be placed thought fully in the bench well in such a way that they do not  rub or knock against other tools, especially those of cast steel. The file should never be used on hardened steel or hard surface scale such as cast iron skin or hard strike against the hardened vice jaws. New files are generally first used on copper, brass, and later on wrought iron and mild steel. Filing, especially the filing or soft metals, causes the file teeth to become clogged with particles of metal. Worn files are useful for marking scraper, punches, chisels, etc. they are also useful on the soldering bench when vet inning soldering irons..