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Flashcards in Sheet Metalworking Review Questions Deck (18)
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Identify three basic types of sheetmetalworking operations

  • cutting
  • bending
  • shearing


In conventional sheet metalworking operation, (a)what is the name of the tooling and (b) what is the name of the machine tool used in the oepration

(a) punch and die

(b) stamping press


In blanking of a circular sheet-metal part, is the clearance applied to the punch diameter or the die diameter

blank diameter = die diameter


punch diameter smaller by twice the clearance


What is the difference between a cutoff operation and a parting operation


shearing operation in which blanks are separated from a sheet metal strip by cutting two opposite sides of the part in sequence from a sheet metal strip



cutting a sheet metal strip by a punch with two cutting edges that match the opposite sides of the blank


what is the difference between a notching and seminothcing operation


cutting out a portion of metal from the side of the sheet/strip



removing a potion of metal from the interior of the sheet


Describe each of the two types of sheet metal-bending operations: V-bending and edge bending


sheet metal is bent between a V-shaped punch and die


Edge Bending

involves cantilever loading of the sheet metal


For what is the bend alloawnce intended to compnesate

stretching of the metal that occurs in a bending operation when the bend radius is small relative to stock thickness


WHat is spring back in sheet metal bending

increase in included angle of the bent part relative to the included angle of the forming tool after the tool is removed


tendency of metal to partially return to its original state after a bend. 


Define drawing in the context of sheet metal working

sheet metalworking operation used to make cup-shaped, box-shaped, complex-curved, and concave parts


what are some of the simple measures used to assess the feasibility of a proposed cup-drawing operation

  • drawing ratio
    Dr = D/Dp
  • reduction
  • thickness to diameter ratio


Distinguish between redrawing and reverse drawing


If shape requiring drawing is too severe, complete forming of the part may require multiple drawing steps, redrwing is that second step


Reverse drawing

drawn part is positioned face down on the die so that the second drawing operation produces a new configuration.


What are some possible defects in drawn sheet-metal parts

  • wrinkling in flanges
  • wrinkling in walls
  • tearing
  • earing
  • surface scratches


What is embossing

forming operation used to create indentations in the sheet, such as raised lettering or strengthening ribs


some strecthing and thinning of metal involved


what is strecth forming

simultaneously strecthing and bending the sheet-metal work part to achieve shape change


what are two basic catagories of structural frames used in stamping presses

straight sided frame presses


gap frame presses


What is the Guerin process

uses a thick rubber pad to form sheet metal over a positive form block


what are the relative advantages and disadvantages of mechanical presses versus hydraulic presses in sheet metal working



Not limited to deep drawing and other operations involving load-stroke characteristics


difference between roll bending and roll forming

roll bending

operation in which usually large sheet-metal or plate-metal parts are formed into curved sections by means of rolls


roll forming

continous bending process in which opposing rolls are used to produce long sections of formed shapes from coil or strip