- Forging Materials
- Forged Shapes
- Industries We Serve
- About Us
- Sales Locations
Open Die Forging
The forging metal forming process has been practiced since the Bronze Age. Hammering metal by hand can be dated back over 4,000 years ago. The purpose, as it still is today, was to change the shape and/or properties of metal into useful tools.
Forging changes the size and shape, but not the volume, of a part. Our Open Die process is still the preferred method for individual forgings. This process results in: metallurgical soundness and improved mechanical properties. Strength, toughness, and general durability depend upon the way the grain is placed. Hammer forging can produce a wide variety of shapes and sizes and, if sufficiently reduced, can create a high degree of grain refinement at the same time.
Types of forging:
Forging is divided into three main methods: hammer, press, and rolled types.
Hammer Forging (Flat Die)
Preferred method for individual forgings. The shaping of a metal, or other material, by an instantaneous application of pressure to a relatively small area. A hammer or ram, delivering intermittent blows to the section to be forged, applies this pressure. The hammer is dropped from its maximum height, usually raised by steam or air pressure. Hammer forging can produce a wide variety of shapes and sizes and, if sufficiently reduced, can create a high degree of grain refinement at the same time. The disadvantage to this process is that finish machining is often required, as close dimensional tolerances cannot be obtained.
This process is similar to kneading, where a slow continuous pressure is applied to the area to be forged. The pressure will extend deep into the material and can be completed either cold or hot. A cold press forging is used on a thin, annealed material, and a hot press forging is done on large work such as armor plating, locomotives and heavy machinery. Press Forging is more economical than hammer forging (except when dealing with low production numbers), and closer tolerances can be obtained. A greater proportion of the work done is transmitted to the workpiece, differing from that of the hammer forging operation, where much of the work is absorbed by the machine and foundation. This method can also be used to produce larger forgings, as there is no limitation in the size of the machine.
Open and closed die operations can be used in forging. In open-die forging the dies are either flat or rounded. Large forgings can be formed by successive applications of force on different parts of the material. Hydraulic presses and forging machines are both employed in closed die forging. In closed-die forging the metal is trapped in recessed impressions, which are machined into the top and bottom dies. As the dies press together, the material is forced to fill the impressions. Flash, or excess metal, is squeezed out between the dies. Closed-die forging can produce parts with more complex shapes than open-die forging. Die forging is the best method, as far as tolerances that can be met, and also results in a finished part that is completely filled out and is produced with the least amount of flashing. The final shape and the improvement in metallurgical properties are dependent on the skill of the operator. Closer dimensional tolerances can be held with closed die forgings than with open die forgings and the operator requires less skill.
Open Die Forging Photos
Click on an image to enlarge it.
Contact one of our Sales Representatives today
to inquire about a quote from Anderson Shumaker
or call us today at 800-932-0357