What is Cold-Heading?

Below is an example of a simple single die,
two blow Cold-Heading process.

Upsetting (creating a bulge in the blank) or extrusion (reducing the diameter of the blank) is essential in controlling and reconfiguring the raw material into its desired final shape. Multiple station machines make it possible to move the work piece through a progression of dies rather than try to form the part in just a few blows.


Advantages of Cold-Heading

1) Design Versatility:
Cold-Heading has a high degree of design versatility and should be considered as an economical alternative to expensive machining. Although some components might not lend themselves to this process, either due to low annual volume requirements or incompatible shapes, there are many advantages of Cold-Heading (over other methods of manufacturing) which should be considered when a part is being designed.

2) Very High Production Rates and Repeatability:
Precision Cold-Heading equipment is capable of producing complex components at remarkably high speeds and with incredible accuracy and repeatability.

3) Close Tolerances:
Standard industry tolerances are typically expressed at plus or minus 0.005. However, with highly precise Cold-Heading equipment, coupled with excellent tooling, diameter tolerances of plus or minus 0.0005 are attainable.

4) Reduced Scrap:
Reduced scrap is a primary area where Cold-Heading is a far more economical process
than machining. The machining process begins with bar stock in the diameter equivalent to the largest diameter of the component being machined. The final shape is achieved by machining away the bar stock thus reducing diameters and creating scrap in the form of shavings. The higher the price of the raw material (such as brass or copper), the higher the loss due to the machined scrap.

The Cold-Heading process begins with an engineered blank and forms the raw material through a series of dies. This forming progression will yield a final product through the re-shaping of the initial blank without generating any scrap! The volume of the finished part is equal to the volume of the initial blank. Cold-Heading is essentially Scrapless!

5) Strength:
When machining a component, metal is cut away to reduce the diameter and create the general outline of the part. By removing the metal, you also remove and "interrupt" the grain structure thus weakening the part. The part was actually stronger in its original bar stock configuration.

Cold-Heading increases strength imparted to the component through the reconfiguration of the grain flow. No material is removed as it is during the machining process. Instead, the upsetting and extrusion process will cause the grains to be compacted and the grain flow itself will be positively altered in critical areas of the part. This rearrangement and compacting of the grain flow yields parts that are more resilient to fatigue. They will have higher shear, tensile and yield strength as a result.

Saras & Associates will assist your company with the design, engineering, manufacturing of prototype samples and complete full production of your new or existing products.

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