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Closed die forgings can be made under a hammer, or press or an upset forging machine. |
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In the case of a press, the preliminary forging operations usually include a minimum of three forging sequences in separate dies in the same set-up. These operations commonly include a flatten, block and finish utilising the same heat and progressing left to fight across the bottom tool holder or bolster of the press. |
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With hammer forging the various preform shapes and the finisher cavity are set out in the one die block. Usually with hammer work multiple hits are given in each cavity to produce the desired shapes. Unlike a forging press the hammer can be controlled via a foot pedal to give tight or hard blows. The application of a light blow to bend the metal into a given shape is advantageous and helps to improve die life. closed die forgings |
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In many instances with more complicated forgings, additional preforming operations may be carried out prior to hammer or press forging. These include reducer rolling, swaging or bending although loss of forging heat when carrying out this additional work may be a problem and reheating may be necessary. |
