10 April 2019

Difference between drop forging and press forging

Drop forging is when half of the die is dropped from a height onto the other half of the die, that will contain the hot metal workpiece to be formed and is more suitable for mass production. Press forging is instead of dropping half the die onto the other half the two halves are put together and pushed together under a large pressure to forming the object. 

Main difference : 

The difference is that drop forming leaves the center of the metal not so hard as the outside, but the press forming gives more uniform hardness for larger components. We could also differ forgings from its temperature, such forgings are named cold forging, warm forging, and hot forging. 

Difference :

  • The metal is shaped by means of a series of blows in drop forging while in press forging, the metal is shaped by means of a single, continuous stroke. 
  • The pressure applied is impacted, and in multi-stroke in drop forging, while the pressure applied is slow, steady and continuous in a single squeezing action in case of press forging. 
  • The deformation of metal is more at the surface layers than that of a center of the metal in case of drop forging, while it is uniform, simultaneous and deep penetrating at the center of the metal part. 
  • The jarred impressions are obtained in drop forging while impressions obtained in press forging are clean. 
  • The draft angles used are more in case of drop forging than that of press forging. 
  • Tong holds are normally required for manipulating dies in drop forging whereas in press forging tong holds are not required. 
  • The initial cost of drop forging is less as compared to press forging. 
  • The drop forging is suitable for almost all types of medium size forgings and press forging is recommended when machine utilization is quite high. 
  • The drop forging is a relatively slow process and has moderate production rates where press forging is a faster and higher production rate.