The phrase "cold forming including heading, upsetting, extruding - is a high speed manufacturing process that produces parts by metal flow due to machine applied pressure as opposed to metal removal by cutting.
Cold forming is the primary manufacturing operation of the fastener industry. But, the capabilities of forming go far beyond just the manufacture of fasteners extending into almost infinite variety of special designed parts. The cold forming process is done in machines generically known as headers.

Beyond the obvious advantages of speed and material savings, for example, some nonsymmetrical shapes can be cold formed but not machined, or a single cold formed part may replace two or more individually produced components. 

Increased Strength - Because cold forming produces grain orientation that follows the contour of the upset, greater strength - as much as 20% or more - is achieved.
Tolerances - Tolerances can be held extremely close on several features of a part design, particularly when relaxation of tolerances can be permitted at other, non-functional areas.
Secondary Operations - Secondary operations can be used to produce added features or more precise dimensions, beyond the many features that can be incorporated into cold forming dies. Most common secondary operations are: Flattening - Bending - Shaving - Slotting - Piercing - Drilling Tapping - Machining - Trimming - Milling - Broaching - tapering - Pointing - Polishing - Plating - Grinding - Knurling - Threading.