Recent questions and answers

Constructional features and Working of Progressive Die:  A progressive die consists of the following parts. 1. Stop 2. Sheet metal 3. Pilot 4. Blanking punch 5. Ram 6. Piercing ... 7. Piercing punch: The function of piercing punch is to produce punched holes into the sheet metal. 

difference between Lappin and Buffing process : Sr. No.  Lapping Buffing 1 Lapping is a finishing process in which tool used is called as lap.   Buffing ... , sporting items, tools, store fixtures, commercial and residential hardware and household utensils and appliances.  

Procedure for developing part program There are two methods of part programming: manual part program and computer assisted part programming. Manual part programming: 1. To prepare a part program using the ... . 5. The NC system machines (makes) the part according to the instructions on tape. 

1. Absolute Co- ordinate system: In Cartesian co ordinate geometry system using absolute measurement. Each point is always specified using same zero of given co ordinate system as shown in fig. It is ... to the system as a distance increment, measured from preceding point. Example:    

Working Principle of CNC machine:- A CNC machine also has a tape reader or any other input media for entry of the part program. CNC uses the part program in a different manner though there is ... to the reference. These two signals are compared and necessary action is controlled.   Or  

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Advantages of CNC Machines:-  [1] Greater machine utilization. [2] Complex machining operations can be easily done. [3] It gives high degree of accuracy. [4] It requires less inspection. [5] ... tooling cost. 6) Temperature, humidity & dust must be affect machining. 7) Initial cost is high. 

Tumbling process: Tumbling process is used for removing rust and scale from metal parts. In this dry abrasive (deburring compounds) are effective for removing rust and scale from small parts of ... from the product. Parts configuration and size are the primary limitations of the process 

Galvanization or galvanisation or galvanizing is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which parts are ... 5. All sort of containers 6. telegraph wire 7. fencing materials 8.Transformer parts

Advantages: 1. Less complex or low cost fixtures. 2. It is highly accurate. 3. It can be used for both long and short bores. 4. It maintains original bore centerline. 5. Any ... rotated or supported. If the workpiece is thin, even hand pressure may cause a slightly oval hole. 

Resistance Welding Process: 1.Resistance Spot welding:  Spot welding is employed to join overlapping strips, sheets or plates of metal at small areas. The pieces are assembled between two ... welding small parts. Butt Welding provides joining with no loss of the welded materials.  

Answer: 1. Stop 2.Sheet metal 3.Pilot 4.Blanking punch 5.Ram 6.Piercing punch 7.Stripper 8.die Fig. Progressive Die OR

Oxidizing Flame: An oxidizing flame is one in which there is an excess of oxygen. The flame has two zones- the smaller inner cone which has purplish tinge, the outer cone or envelop.   Carburizing ... defined inner cone 2) An intermediate cone of whitish colour. 3) Bluish outer cone   

MIG Welding: Gas-metal-arc welding is a gas shielded metal arc welding process which uses the high heat of an electric arc between a continuously fed, consumable electrode wire and the material to be ... will not combine with metal. Carbon dioxide is most commonly used as it inexpensive.

Answer: Comparison of brazing and soldering

Answer: Classification of Welding 1. Arc welding a. Carbon Arc Welding; b. Shielded Metal Arc Welding (SMAW) c. Submerged Arc Welding (SAW) d. Metal Inert Gas Welding (MIG, ... workers 14. Cost of materials 15. Code or specification requirements 16. Mechanical properties desired in joints 

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Answer: Functions of die accessories. 1. Pilots: The pilot positions, the stock strip accurately and bring it into proper position for blanking and piercing operations. They act as guides during the ... 4. Pressure pad: It is used for drawing operation for maintaining flat surface of the cup. 

Blanking: The blanking is the operation of cutting of flat sheet to the desired shape. The piece detached from strip is known a blank. The metal punched out is the required product and the plate with the ... hole and clearance is provided on the die. Fig. shows punch and die set for piercing.  

Answer: OR Functions of important parts of Fly Press. 1. Ram : This is main operating part of the press which works directly during processing of a workpiece. Ram ... : A die is a specialized tool used in manufacturing industries to cut or shape material mostly using a press 

Press Forging: In press forging, impression dies are used in which partd are made by plastically deforming a metal blank into die avities by slow squeezing action. The forging pressure builds up from the ... they are generally employed for non-ferrous alloys weighting from upto about 135 N. 

Classification of forging processes :  1.Open die forging: a) Hand forging b) Power forging:  i. Hammer forging  ii. Press forging 2.Close die forging: a) Drop forging b) Press forging c) Machine forging

Difference between open die and close die forging:

Answer: Forging process used for production of spanner: 1) Fullering -The heated stock is elongated by reducing its cross section in first die.  2) Edging- The metal is redistributed, ... Trimming: Flash is removed   (6) Heat treatment and machining is done as per requirement.   

Answer: Advantages of forging processes  1) Complex shaped parts can be forged 2) Mass production with greater accuracy is achieved. 3) It is very easy to maintain close tolerances. 4) ... cannot be produced by forging. 8) Rapid oxidation of metal surface at high temperature wears the dies 

Forgeability: Forgeability can be defined as the tolerance of a metal or alloy for deformation without failure. OR  Forgeability is defined as the ability of a metal to change size and shape when heated to ... 10) Tantalum alloys 11) Molybdenum alloys 12) Tungsten alloys 13) Beryllium.

Answer: Classification of CNC machines according to number of axes 1. 2 axes CNC Machine 2. 3 axes CNC Machine 3. 4 axes CNC Machine 4. 5axes CNC Machine

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Answer: Surface cleaning processes I. Chemical Cleaning a. Solution b. Saponification c. Emulsification d. Dispersion e. Aggregation Depending on cleaning fluids used, types of chemical ... . Power brushing e. Machine polishing & buffing III. Ultrasonic cleaning IV. Flame cleaning 

Answer: 1. Neutral Flame 2. Oxidizing Flame 3. Carburizing Flame 

Answer: Applications of resistance welding: 1. Resistance welding is widely used in automotive industries. 2. Projection welding is widely used in production of nut and bolt. Projection welding is ... welding is applied in manufacturing of wheel rims, wire joints and railway track joints etc. 

Answer: Materials used in press work  1) Aluminium, 2) copper, 3) brass, 4) mild steel, 5) Galvanized iron (G.I) sheets, 6) Duralumin, 7) Y-alloys, 8) naval brass, 9 ... ) Babbitt metal, 11) stainless steel & its alloys, 12) Different types of steels & its alloys.

Answer: Different types of forging method - I. Open die forging: a) Hand forging b) Power forging: i. Hammer forging ii. Press forging II. Close die forging: a) Drop forging b) Press forging c) Machine forging OR

(i) Difference between Open Die and Close Die Forging: (ii)Drop Forging  Drop forging is carried out by using drop hammers. They are board or gravity hammer, air lift hammer and power drop ... of upper and lower dies. The ram is fastened to the lower end of vertical hard wood board.

Principle of Lapping: Lapping is basically an abrasive process in which loose abrasives function as cutting points finding momentary support of the lap. The process has the following features. (a) Use of ... roller bearings ii. Gears iii. Piston rings iv. Slip gauges v. Crankshaft.

Axis Configuration for Horizontal Spindle CNC Machines: The first axis to be identified is the Z axis. This is then followed by the X and Y axes respectively. Z Axis and ... are in the directions which advance right-hand screws in the positive X, Y and Z directions respectively.  

Reference Positions used on CNC Machine: There are Four reference positions on CNC machine: 1. Machine zero point 2. Work zero point 3. Tool home position. 4. Parking Position 1. Machine Zero Point: ... to move out of the way (usually to the back of the machine) after a job has completed. 

Tools used on Turning Centre: 1. External Turning Tools: 2. Boring Bars:   3. Drills:   4. Threading Tools:   5. Parting Tools:   A. On the Basis of Cutting Tool Construction: ( ... (HCS). (c) Cast alloy. (d) Cemented carbide. (e) Ceramics. (f) Boron Nitride. (g) Diamond. 

Incremental programming methodIn Cartesian co-ordinate geometry system using incremental measurement. Each point is always specified using the path differential from the preceding point position. So in such a ... applied to the system as a distance increment, measured from preceding point.

Differentiate between CNC and DNC machines: S. N. CNC DNC 1 In CNC, Far off controlling of operation is not possible DNC facilitates far-flung control  2 ... DNC now not only controls the equipment; however, also serves as a part of administration statistics system.

Classification of CNC machines. A. According to control loop feedback system: 1) Open - loop system 2) Closed - loop system B. According to type of tool motion control system: 1) Finite ... D. According to type of controller: 1) NC based controller system 2) CNC based controller system

Components of CNC machines The various components of CNC system are :- 1) Program Input Device:- It is the medium of transmitting the part program to the computer. Three commonly used program input ... to facilitate a two way communication between the user, CNC system and the machine tool.

Honing Process (micro finishing process): To correct hole geometry in component, honing is used as a micro finishing process. Honing is an abrading process used mainly for finishing round holes by means ... operation of this process, to flush away small chips and to keep temperatures uniform.

Abrasive Blast Cleaning (Blasting): This method is widely used for removing all classes of scale and rust from forgings, castings, weldments, and heat treated parts. Depending on the finish ... and other material are removed, providing an excellent surface for bonding final finishes.

Comparison of Electroplating and Galvanizing process: 

Tungsten Inert Gas Arc Welding (TIG, GTAW): It is a welding process, in which heat is generated by an electric arc struck between a nonconsumable tungsten electrode and the work piece. The weld pool is ... produces a high quality weld of most of metals. Flux is not used in the process.  

Progressive Die: In a progressive die two or more operations are performed simultaneously at two or more stations with each press stroke by mounting separate sets of dies and punch. The metal is progressed ... locate it while the blanking punch descend and shear the plate to form a washer.  

Types of Flames: Characteristics Applications. 1)Neutral Flame: When oxygen and acetylene are supplied to the torch in nearly equal volumes, a neutral flame is produced. It has two ... cone of whitish colour. 3) Bluish outer cone High Carbon Steel, non - ferrous alloys,

Classification of Welding Process Depending on method of heat generation American welding society classifies welding as A. Arc Welding 1) Carbon Arc Welding; 2) Shielded Metal Arc Welding (SMAW) 3) ... . Thermit Welding (TW) F. Electron Beam Welding (EBW) G. Laser Welding (LW) 

Method of Welding Used in Manufacturing Sheet Metal Roofs and doors of automobiles: MIG Welding: Gas-metal-arc welding is a gas shielded metal arc welding process which uses the high ... mixtures) which will not combine with metal. Carbon dioxide is most commonly used as it inexpensive.