Mechanical Engineering Technical Interview Q & A_Press tools PDF
- 1. Press Tools Top Manufacturing and Industrial Engineering Interview Questions on Press Tools with best explanation for mechanical interview, competitive exams and entrance test. 1. What is a tool ? Anything which is necessary to make a product is called tools. 2. What are the classification of tools ? Press tools, Moulds, Jigs and fixtures, Cutting and assembly tools ,gauges and measuring instruments. 3. What is a press tool ? Press tool is a custom built tool in which we make sheet components that not readily available in the market. 4. What do you mean by stampings? The sheet metal which makes with the help of press tool is called stampings. 5. Name the different types of rolling ? Hot rolling, cold rolling. 6. What is Stock materials ? Sheet metal from which stampings made is called stock material. 7. What are the press tool operations ? Cutting, non cutting and combination of both. 8. What is strip? Each piece of sheet metal called strip. 9. What do you mean Blanking ? In this operation, cut out material or slug will be the component. 10. What is piercing? Process of making opening on sheet metal is called piercing. The cut out material will be waste. 11. What is called cutting off ? Material is going to cut in a single line, there won’t be any waste. 12. What is parting off ? Double line cutting material in between the line will be waste.
- 2. 13. Describe about a side cam tool? Transforms vertical motion of the press ram into horizontal motion of the tool. It is used for side piercing. 14. What is perforating ? Making no. of holes at a time. 15. What is dinking ? Press tool cutting operation for soft materials like paper, leather, wood etc. 16. What is trimming ? Removing large amount of material from the edge of the piece part. 17. What do you understand shaving ? Removing small amount of material from the previously blanked part. 18. What is broaching ? Series of teeth profile removes metal from blanked part. 19. Describe bending? Bending can be explained as shaping of material around straight line axis. Result is a new plane which is at an angle to the mother plane. 20. What is lancing ? Combination of cutting and bending. 21. What is forming ? Press tool non cutting operations in which material is formed into different shapes. 22. What do you mean drawing ? Process of making cup or vessel is called drawing. 23. What is curling ? Rolling the edge of sheet metals. 24.Define bulging? Internal forming operation to expand portions. 25.Name the common medias of bulging ? rubber, urethane, oil etc. 26. What is swaging? Opposite of bilge. External forming operation also called as necking. 27. What is extrusion ? Operation to produce collapsible tubes, shell etc.
- 3. 28. Define coining? Making depression and corresponding projection won’t be there. 29. What is an assembly tool ? Assembling of two or more parts by riveting, press fitting etc. 30.Describe flaring, lugging, collar drawing ? Making collar so that no. of threads can be provided. 31. What is Planishing ? Flattening of material is called Planishing. 32. What is progressive tool ? Multi stage tool in which perform work at number of stations. 33. What is compound tool ? All cutting features of the component perform at one stroke of the ram. 34. What do you meant by combination tool? Small press operated in large one. Blank and form very small parts. 35. What is notching ? Small amount of material cuts from the edge of the component. 36. What do you understand by sub press tool ? Small press operated in large one, blank and form very small parts. 37. What is louvering? Combination of cutting and forming. 38. What is shearing? Method of cutting sheets without forming chips. 39. What are the stages of shearing ? Plastic deformation, penetration, fracture. 40. Result of plastic penetration stages is ? Cut band 41. Result of plastic deformation stage is ? Edge radius or roll over. 42. Result of fracture stages is ? Break edge. 43. Name the types of shear load ? Internal and external loads.
- 4. 44. What are the types of external shear load ? Compressive load and tensile load. 45. Define tensile load ? Force acting on opposite direction in same axis. 46. What is shear load ? Load which is acting on same direction but not in same axis. 47. What is compressive load ? Forces acting on same direction in same axis. 48. Name the types of force based on speed ? Impact force (quick force) magnetic force 49. Describe about stress ? Load acting on a material per unit area. 50. Formula of stress ? load /area 51. What is cutting force? The force which acts on sheet metal to cut the blank. 52. Formula of cutting force ? Fc = LSTmax L : Length of periphery to cut in mm. S : sheet thickness in mm TM ax : shear strength in n/mm^2 53. Shear strength is …. % of tensile strength. 80% 54. Equation to calculate press force ? Press force = cutting force + stripping force 55. Normal stripping force is ? 10 to 20 % of cutting force . 56. What are the methods to reduce cutting force ? Using stepped punch. Grind the face of the punch or die to a small sheared angle
- 5. 57. For blanking shear angle will be on ? Die. 58. For piercing shear angle will be on ? Punch 59. Briefly explain the capacity of the press ? Maximum amount of force can be given on the press . It is determined by KN or TONS. 60. What is the shear strength ? Ability of material to resist shear stress. 61. 1 TON =……. Kgf 1kgf. 62. What is reason of drill breakage ? Due to torsion and compression 63. U channel and angle iron made by ….. process Extrusion 64. 1N =... kgf 9.8 kgf 65. What do you meant by cutting clearance ? Gap between the side of the punch and corresponding side of the die in single side. 66. Cutting clearance is expressed as ... ? Mm /side 67. Result of optimum cutting clearance will be....? Maximum cut band. 68. Result of excessive cutting clearance will be ...? Maximum edge radius. 69. Result of insufficient cutting clearance will be...? Maximum break edge. 70. Punch determines....? Piercing size 71. Die determines ...? Blanking
- 6. 72. Calculation of cutting clearance ? Sheet metal up to 3mm = C*S* root of (TMAX/10) Sheet metal more than 3 mm=(1.5*s) *(s-0.015)* root of (TM ax /10) 73. What is called land ? To avoid jamming of material inside the die ,we give straight portion of certain amount from the cutting edge. That is called land. 74. For sheet metal S up to 3 mm = land will be....? 3mm 75. For sheet metal more than 3 mm = land will be...? Sheet thickness. 76. Usually ,angular clearance is provided in ... Degree ? 1.5 degree /side. 77. Generally, soft material require... Angular clearance ? more. 78.What are the types of guide plate tool ? Open guide plate tool Stripper guide plate tool 79. Name the basic elements of tool ? Punch and Die. 80. Punch and die materials ? Good quality alloy steel(HcHcr ,D2). 81. Hardness of punch ? 58-60 HRC. 82. Hardness of die ? 60-62 HRC. 83. Stripper plate material ? MS or medium carbon steel 84. Thrust plate material ? OHNS. 85. Hardness of thrust plate ? 45-48 HRC
- 7. 86. Top plate and bottom plate material ? MS or Cast iron. 87. Screws are to ……… the parts ? hold 88. Dowels are to ………. the parts ? align 89. Name the types of cold rolled stock materials used ? Hard, Three quarter hard, Half hard, Quarter hard, Soft, Dead soft. 90. What is the specialty of hard sheet metal ? Can not bend. 91. What is the specialty of 3 quarter hard material ? Can bend 60 degree across the grain. 92. Specialty of half hard material ? Can bend 90 degree across the grain. 93. Quarter hard material ? Can bend 180 degree across and 90 degree along the grain direction. 94. Soft material ? Can bend 180 degree across and along. 95. Dead soft material ? Can be formed into different shapes. 96. What is strip lay out ? A layout which gives sequence of works and operations. 97. What are the factors effecting a strip layout ? Shape of the blank, production requirement, grain direction, burr side, stock material. 98. Formula of economic factor ? (area of the blank*no. of rows )/(pitch*scrap width ) 99. What is pitch ? Distance between two consecutive operations. 100. What is scrap bridge ? Portion of the material remaining between two adjacent openings. 101. Scrap bridge nearer to the operator called .... scrap ? Front scrap
- 8. 102. Scrap bridge away from the operator called .... scrap? Back scrap 103. What are the types of strip layout ? Single row layout, double row, gang dies and angular. 104. Name the types of single raw layout ? Narrow run, wide run 105. List about the types of punches ? Cutting punch, non cutting punch and hybrid punch. 106. What are the groups of punches ? Segregated punches and integrated punches. 107. What is segregated punch ? Self mounted by screwing etc. 108. What are the integrated punches ? Mounting with the help of punch plate etc. 109. For beveled head punch bevel angle is .........? 30 to 45 degree 110. What is perforator? Punch of diameter 2mm and below. 111. What is bucking force ? Maximum force a punch can withstand without bucking. 112. Formula for buckling force ? Fb =(ii2EI)/LP2 113. Modulus of elasticity of Steel ? 200 to 220 GN/M2 114. Unit of moment of Inertia ? Mm4 115. The ultimate condition of buckling force is ……..? Buckling force =cutting force require for the operation =shear force on the punch 116. Material of solid die ? Non shrinking tool steel. 117. Die bushes are inserted in …..? mid steel retainer plate.
- 9. 118. Dies having more than one section called ....? Split dies 119. Material of carbide dies ? Tungsten carbide 120. What is the function of stopper ? Arrest the movement of the strip for one pitch length after each stroke. 121. Fundamental principles of stopper ? Stop position and registry position. 122. What is stop position ? Actual position of the stopper. 123. Describe registry position ? Exact position where strip has to be established. 124. Types of strippers? Fixed and traveling 125. Function of stripper ? Strip the stock material off the punches after each stroke. 126. Tunnel width formula ? X = w + f w = stock strip width at maximum tolerance f = desired horizontal feeding clearance 127. Hook pins are made from ……….? Cold drawn steel rod 128. Gauge thickness for the material up to 1.5 mm is .... ? 3mm 129. Gauge thickness for the material more than 1.5 mm is ... ? Sheet thickness +1.5 mm 130. Prevention of wrong loading can be done by... ? Fool proofing