Machine Marking and Marking Tools.pptx

I make this ppt for engineering students to help us the marking and marking tool understand about the marking tool. This ppt for fitter mechanical engineering base on marking and marking tools to understand the basic fundamental. The current needs of students and teachers engaged in skill training.

1. Marking and Marking Tools Presented by Name: Irfan saudagar Unit: Workshop tools Date: 06-03-2023

2. Purpose of Marking To ensure that the correct amount of metal is removed from the various faces so that the correct shape is produced. To Provide lines which will serve as a guide indicating that a correct size has been reached

3. Marking Media Marking media, as   metal  is a hard material, so the drawn lines are not clearly visible hence marking media is used . In this way, the marking media is a material that is applied on the surface on which marking has to be done by  marking tools   so that the lines of marking can be seen clearly.  Marking media can be divided into four categories White Wash Prussian Blue Copper Sulphate Cellulose Lacquer

4. Method of Marking Media Datum line method Center line method Marking by Template Marking of C entre on round rod end 1. By Jenny Caliper 2. By surface Gauge 3. By Centre head of combination 4. By bell Punch https://youtu.be/PssrSGRxNk8

5. jenny caliper and Surface gauge

6. Hints to be noted while marking Study the workpiece drawing carefully. Check proper application of marking media on the surface of workpiece. Mark first straight horizontal, vertical and inclined ones, and then circles, arcs, curve. After completion of marking clean the job and tolls used for this purpose.

7. Types of Marking Tools & Their Uses

8. Surface Plate A surface gauge is a marking tool or marking out tools that are used  to  draw a line of layout work by  placing them on a surface plate.  This is a precision machined surface. It is made of cast iron, graphite, or ceramic.  Some surface plates are flat by  lapping  to a precision of 0.0025 mm.  It is used to test the flatness of other surfaces or marking off the work and used for inspection of  jig and fixture  as well as gauges.

9. Marking Table   This is made from closed grain cast iron and is given special  heat treatment  so that it does not   change  its size after  use. The marking table provides a reference plane on which the   task and marking-out tools are  placed. The work that needs to be marked, is placed at a right angle with the reference plane. When it is not to be used, it should be covered with a well fitting wooden cover to protect it.   

10. Scriber Scriber is the very most importa - nt marking out tools in mechani - cal workshop or fitting shop. A scriber is a hand tool used in metal work to mark lines on workpieces, prior to machining . This hardened tool is a sharp tool made of high carbon   steel  that is used to draw lines while marking   on a metal  job.  It  has a Conical Point (top angle usually 159 °) and a knurled body. 

11. Divider This is a marking tool or marking out tools used  to mark circles, segments, and other geometrical textures.  It made of brass with steel points. It  is also used to transfer textures. It is made of tool steel, and its points are hardened and tempered.  It is classified according to the maximum number of points it can open.

12. Surface Gauge A surface gauge is a marking tool or marking out tools that are used to draw a line of layout work by placing them on a surface plate.  It is made of steel. Surface gauge can be classified by the height of the spindle. There are two types of surface gauges: 1. Fixed Type Surface Gauge.:- Its  design consists of a heavy base and a spindle that is a straight fix and it is fitted with a scriber with a snug and a clamp nut . 2. Universal Surface Gauge.:- This surface gauge has the following additional features: Can  set the spindle in any position Fine adjustments can be made quickly. It can also be used on cylindrical surfaces. 

13. Punch Punches are  usually classified according to the shape of their points .  There are two types of Punches.: 1. Prick Punch  A prick punch is a layout marking tool or marking out tools that are made of steel, approximately 100 mm to 150 mm.  It is long, with both ends hard and tempered.  Its point is  grinded  at an angle of 30°. It is used to place small dots on layout lines, punch marks on the center of drill holes . 2. Center Punch It is like a prick punch but its point is grinded at an angle of about 90 °. 

14. This is used to make the marks larger than the prick punch because the point of the  drill  sits easily in it and the drill can be easily done with precision.  Some center punches are automatic with a striking mechanism in the handle. 3. Dot punch: The dot punch is a lighter and thinner version of the center punch and is used basically for the same job. However, it is more accurate as the dot produced is smaller . In general, Dot Punches have a sharper point (i.e. 60° instead of 90°) and need only the lower ranges of impact force (e.g. 20N to 50N). The centre punch is made from mild steel

15. V-block It can be classified into different grooves,levels,clamps (or) grades.  V 'blocks are often made of hardened steel or cast iron, which are found in many sizes.  These are often used for drilling on layouts or round work.  They are usually found in pairs and have a V-shaped slot machined at a perfect 90 ° angle at its top and bottom. Often a 'U' shaped clamp comes with it tied tightly to the work.

16. Angle plate Angle plates can be classified as size, shape and intented use. Angle   Plates are used to hold the work in parallel and at right angles to the surface. A 'C'  clamp device  is often used to hold the work on the angle plate. Some angle plates have slots and tapped holes to hold the work . Angle  plates are found in various size which  are in the range from 1 to 10 numbers.   Angle plates are made from high quality material (generally spheroidal cast iron)

17. Try square It is a precision instrument which is used to check squareness of a surface. It is made from a special hardened steel. Its size is specified by the length of its blade. Its three main uses are a) to determine if two surface are right angles to each other. b) to check the surface for flatness. c) to layout lines at right angles to a machined surface. The accuracy measurements of try square is about 0.002mmper 10mm length.