Friday, 27 April 2018


          A file is a multi-point cutting tool, which is used generally to remove fine amounts of material by rubbing it on the metals or parts. Most of the files are made of high carbon steel, where the length has been hardened and tempered, but the Tang of the file has been left soft. Files are manufactured in a wide variety of materials, designs, sizes, and tooth configurations. Files have also been developed with abrasive surfaces, such as natural or synthetic grains of diamond or silicon carbide, allowing removal of material that would dull or resist metals, such as Ceramics.
Image Courtesy:
          There is no universal standard for nomenclature of a file; they are known by their cross-section, the general shape or by their particular use. The file we use is dependent on the type of work we are doing and material we are using. There are many commonly accepted names for certain kinds of files. A file is called "Blunt" if its sides and width are both parallel through its length. It is "Tapered" if they having converging edges from its heel towards its point. A file may taper in width, in thickness, or in both. A "Tang" is a protrusion at the heel, tapered, parallel sided, or conical for gripping, inserting in a handle, or mounting in a chuck.
          Files are used to square ends, to make rounded corners, remove burrs, straighten uneven edges, file holes and slots, etc., The safe edge of a file does not have teeth. This is extremely useful when filing in corners. The safe edge is placed into the corner and because it is smooth it does not damage the surface of the metal.

We can discover more details about the parts of file below.
. The Point is sometimes called the top, (for apparent reasons).
. The Shoulder can also be called the Heel.
. Files have  cutting teeth on both faces. In the case of the Hand file, only one of the edges has teeth on it and the other is smooth, and called the safe Edge. The safe edge allows us to rub the file up against a surface without wearing any material away.
. Always make sure that the Handle is securely attached to the Tang, otherwise we could give our self a nasty injury.
. The length of the file (Commonly measured in mm), is measured from Shoulder to the Point. 

Files have three distinguished features, and are classified by the below features:
1. Length
2. Cross section or shape
3. Grade of cut.

Classification of files:
i. On the basis of length:
     4", 6", 8", 12" etc 
ii. On the basis of Grade:
     1. Rough (R) (20 teeth per inch) 
     2. Bastard (B) (30 teeth per inch)
     3. Second cut (Sc) (40 teeth per inch)
     4. Smooth file (S) (50 teeth per inch)
     5. Dead Smooth (DS) (100 teeth per inch)
iii. On the Basis of number of Cuts:
     1. Single cut files
     2. Double cut files
     3. Rasp files.
iv. On the basis of Shape
a. Flat file:
          Flat files are flat on bottom and top of faces. These files has parallel edges for about 2/3rd of the length and then it tapers towards the point. The both faces are double cut while the edges are single cut.
b. Hand file:
          The hand file breadth is constant throughout it's length, however the thickness tapers as given in falt file. Both faces are double cut and one of the edge is single cut. The remaining edge is kept blank and referred to as safe edge, so as to use for filing a right-angled corner on one side only.
c. Square file:
          It has a square cross-section. Square file has double cut on all it's sides. It is parallel for 2/3rd of it's length then tapers towards the point. It is used for filling square corners and slots.
d. Triangular file:
          It has breadth either parallel throughout length or upto middle then taper towards the tip. It's cross-section is triangular (Equilateral triangle) and also the 3 faces are double cut and the edges are sinle cut. It is used for filling internal angles and corners and for sharpening wodd working saws.
e. Round file:
          It has spherical cross-section. It is usually made tapered towards the tip and is often called Rat-tail file. It carries single cut teeth all round it's surface. Parallel files having same diameter throught the length are acailable. The round files are used for opening out holes, producing round corners, round-ended slots etc.,
f. Half-round file:
          It’s cross-section isn't a real half circle however is only about 1/3rd of a circle. The breadth of the file is either parallel throughout or upto middle then tapered towards the point. This file is double cut at flat side and single cut on curved side. A normal file is not suitable for filing curved surface so it is used for filing curved surfaces.
g. Knife edge file:
          It has a breadth tapered like a knife blade and it is also tapered towards the point and thickness. It carries double cut teeth on the 2 broad faces and single cut teeth on the edge. It is used for finishing sharp corners of grooves and slots.
h. Diamond file:
          It is used for only for special purpose work. It has a cross-section like a diamond. 
i. Needle file:
          These are slender files having a parallel tang and a thin, narrow and pointed blade made in several cross-section that fits it's special requirements. They do not have a Tang however their handle is knurled for grip. They are available in different shapes and cuts and sizes from 100 to 200 mm. These are used for very thin and delicate work.

No comments:

Post a Comment

@2017 All Rights Reserved. Designed by WWW.SMARTWAY4STUDY.COM !!!! Sitemap !!!! Blogger Templates