Enter the diameter of the extrusion die, the diameter of the product, the core diameter, and the outside diameter of the tip into the Draw Down Ratio Calculator. The calculator will evaluate and display the Draw Down Ratio. 

Draw Down Ratio Formula

The following formula is used to calculate the Draw Down Ratio. 

DDR = (DD/PD) / (DT/CD)

  • Where DDR is the Draw Down Ratio ( )
  • DD is the diameter of the extrusion die 
  • PD is the diameter of the product 
  • DT is the outside diameter of the tip 
  • CD is the core diameter

How to Calculate Draw Down Ratio?

The following example problems outline how to calculate Draw Down Ratio.

Example Problem #1

  1. First, determine the diameter of the extrusion die.
    • The diameter of the extrusion die is calculated to be : 5.
  2. Next, determine the diameter of the product. 
    • The diameter of the product is measured to be: 2.
  3. Next, determine the outside diameter of the tip. 
    • The outside diameter of the tip is found to be: 3.
  4. Next, determine the core diameter.
    • This is measured to be 1.
  5. Finally, calculate the Draw Down Ratio using the formula above: 

DDR = (DD/PD) / (DT/CD)

The values given above are inserted into the equation below and the solution is calculated:

DDR = (5/2) / (3/1) = 8.33


Example Problem #2

The variables required for this problem are provided below:

diameter of the extrusion die = 6

diameter of the product = 7

outside diameter of the tip = 8

cored diameter = 4

Test your knowledge using the equation and check your answer with the calculator above.

DDR = (DD/PD) / (DT/CD) = ( )