How to use a cold chisel. Chipping process. Cold chisel. Types of Chisel Tools With Diagram, скачать в хорошем качестве

How to use a cold chisel. Chipping process. Cold chisel. Types of Chisel Tools With Diagram,

How to use a cold chisel. Chipping process. Cold chisel Chisel is used to cut flat, round or angle iron and thick metal sheets. It is also used to remove the unwanted metal from the surface of a job by cutting it in bits and small pieces. This act is known as chipping. The cutting done by a chisel is rough. Therefore, there is need for finishing after chipping done by the chisel. It saves time. Chisels are used both on hot and cold metals. As such chisels have been divided into two categories. Classifications of Chisel Hot chisel Cold Chisel Hot Chisel Hot chisel Hot chisel is used for cutting hot metals in blacksmith’s workshop. There is a hole in a chisel in which a wooden handle is fixed. Their cutting edge is made at an angle of 30°. While using this part, it is frequently dipped into water for making it cold so that its edges remain intact. Cold Chisel Cold chisels are generally used in sheet metal and fitter trade workshops. With cold chisel cutting or chipping of metal can be done when these metals are in cold condition. This is available in 4 sides, 6 sides or 8 sides. These are made of high carbon steel, which contains 0.75% to 1.00% of carbon. Generally, chisel, of 150 mm length is used. Practically, chisels measurement is known from the width of chisels cutting edge. Parts of a Chisel Following are the different parts of a chisel: Head Body Forging angle Cutting edge Cutting angle Head The topmost part of a chisel is called “Head”. It is a bit suck in the middle so that the blow of hammer strikes at the centre of the chisel. Thus, because of repeated blows, its head becomes mushroom. In this case, the chisel’s head should be set right by grinding. While making the head, the upper part of the body should be 10° to 20°. Body That part of a chisel from which we hold it is called the body or stock. It is made of four, six or eight sides so that it is easy to hold. The body is made somewhat flat from the bottom. Forging Angle Some part of the flat position below a chisels body is tapered. This angle of taper is called forging angle. It is also known as Draw Angle. Cutting Edge That part of chisel that performs the function of cutting is called the cutting edge. Its width is taken as chisels measurement. Cutting Angle The angle at which a cutting edge of chisel is grinded is known as its cutting angle. For cutting hard metal, the cutting angle is more and for cutting soft metals the cutting angle is less. While grinding chisels for cutting various kinds of metals their angles should be as under Mild steel – 55 ° Cast iron – 60 ° Tool steel – 65 ° to 70 ° Copper – 45 ° Aluminum – 30 ° Brass – 50 ° Hardening and Tempering of Chisel In order to make the cutting edge last longer even the tapered part of a chisel is made hard and the edge is tempered. For this purpose, chisel should be heated at an appropriate temperature up to half of its length and this edge part of the chisel should be cooled in clean water. This would make that particular part of chisel hard. Then its edge part should be cleaned with a sand-paper. Again it should be heated at an appropriate temperature. would start changing and when it turns into appropriate colour, it should be cooled down in lime-water. This would temper the longer period. Types of Chisel Following are the different types of chisel: Flat chisel Cross cut chisel Side cut chisel Round Nose Chisel Diamond point chisel Cow mouth chisel 1. Flat Chisel In these types of chisel, It is an all-metal chisel used for obtaining a flat surface on metal by chipping. This chisel is used to cut wires, thin sheets and round rods etc. The edge of this chisel is in “V” shape and is flat, which is raised from the centre. Because of this projected parts, it does not get stuck into the cut surface, while chipping. 2. Cross Cut Chisel It is mainly used to cut square slots and channels. Keyway on a shaft is made with this chisel. Its cutting edge is from 3 mm to 12 mm in width. In order to ensure that this chisel does not get stuck into the grooves and slits while using it in the grooves and slits, the part behind its edge is made comparatively thin. Side Cut Chisel Where other types of chisel cannot be used easily, side cut chisels are used. The keyway and cotter way is cleaned with this chisel. Side cut chisel It is almost similar to the flat chisel but the part which performs the function of cutting is turned to one side. It is turned at an angle and then forged. Its cutting angle is generally at and forging angle at an angle. Round Nose Chisel Round nose chisel Its edge is round. It is used for making an oil groove in a bearing and for cutting slits at corners. Its forging angle is at and cutting angle is of 35 ° to 40 °. In such jobs where the drill is dislocated at the time of drilling and some substance is left, the leftover metal is set right with this chisel.