Every Cost Engineer has been tasked with creating a SHOULD COST on a process they are unfamiliar with and the software of choice does not have a method to reliable CYCLE TIME.  So what do you do?  You may do days of research, reading old text books, search the internet and maybe even have to visit manufactures or business that utilize this technology that you are unaware of.

You probably are asking yourself, “Hasn’t someone else had this same request? I can’t be the first to try to model this process.  Is there a place I can get help?”  This is it.

The idea is that if you have developed a method of calculating a CYCLE TIME for a unique process, post it here for others to use.  If you need a CYCLE TIME calculator for a process you are unfamiliar with, check here first.  If you can’t find on  that fits your need, ask the community through the comments section.

NOTE: 1) To add a CYCLE TIME calculator, please use the contact us link on this sight.  The calculator can be in either Excel or Word format.  The site administrator will add it to the list.  2) Use the calculator at your own risk.  It would be strongly advised that you sense check the data, method and results prior to implementing within your own work.

 

6 Comments

  1. Hariharan

    I am looking for cold forging cycle time calculator.

    Reply
    • Jerry Collins

      I’m not an expert at cold forging but hoping others will correct me.

      Usually, the “forging” is in the order of < a second per hit. I think the key becomes how many hits and method of transfer?

      If this is lower volume, they may be set up on a transfer style line so the time may become additive. If it’s higher volume it may be progressive style and therefore it’s only the time per the longest hit (another topic altogether).

      Video I found on YouTube https://youtu.be/VCUJu-5z–s

      Anyone care to correct?

      Thanks for the help.

      Reply
  2. Chandana

    Please share the excel for calculating cycle time and tonnage for forged parts

    Reply
    • Jerry Collins

      Again, not a forging expert but I found this online. Please try it and let me know what you think. If it’s not accurate we will take it down. Welcome your feedback!

      For a time I would use the “Strike Speed” or Strokes per minute. When you depreciate the cost of the equipment correctly, say over 3 shifts, 5 or 6 days a week and anywhere from 7 to 20 year depreciation, I don’t think the machine cost will be a big driver. Similarly labor should be shared across multiple presses and there labor should be minimal as well.

      COLD FORGING
      F=25 x (3.5~6.3) x K x A

      F = Force Required
      K = Steel Coefficient (0.9 for low carbon, 1 for medium and low carbon alloy steel, 1.1 for medium low alloy steel and 1.25 for high alloy structural steel)
      A = Total deformation area of forging plan (Including Skin and flash) (cm2)
      Use lower limit (3.5) for transfer type or low productivity
      Use higher limit (6.3) for progressive dies and high productivity

      HOT FORGING
      F = (64~73) x K x A

      K = Steel Coefficient (0.9 for low carbon, 1 for medium and low carbon alloy steel, 1.1 for medium low alloy steel and 1.25 for high alloy structural steel)
      A = Projected area of the forging including Flash (cm2)

      Speeds
      Steam Hammer Screw Press Crank Press Die Forging Hammer
      Strike Speed (m/s) 4-7 0.6-0.8 0.3-0.7 4-6
      Cold Strike Time (ms) 2-3 30-60 30-60 2-3
      Forming Time (ms) 5-15 30-150 80-120 5-15
      Strike Speed 80-100 6-15 40-80 80-110

      Source: https://www.machinemfg.com/forging-press-selection-and-tonnage-calculation/

      Reply
  3. Jerry Collins

    A bit easier to read

    Steam Hammer
    Strike Speed (m/s) 4-7
    Cold Strike Time (ms) 2-3
    Forming Time (ms) 5-15
    Strike Speed 80-100 6-15

    Screw Press
    Strike Speed (m/s) 0.6-0.8
    Cold Strike Time (ms) 30-60
    Forming Time (ms) 30-150
    Strike Speed 40-80

    Crank Press
    Strike Speed (m/s) 0.3-0.7
    Cold Strike Time (ms) 30-60
    Forming Time (ms) 80-120
    Strike Speed 40-80

    Die Forging Hammer
    Strike Speed (m/s) 4-6
    Cold Strike Time (ms) 2-3
    Forming Time (ms) 5-15
    Strike Speed 80-110

    Source: https://www.machinemfg.com/forging-press-selection-and-tonnage-calculation/

    Reply

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