In heading, an axial blow shortens a portion of the blank and swells its diameter, gathering the volume needed for a head or flange. Only a limited length of unsupported wire can be upset in one blow before it buckles and folds, so large heads are gathered over several stations. The word also names the swollen section itself.
Heard on the job
Too much free length on the first upset, it's folding over instead of filling the die.
Also heard as
- upsetting
- gathering
Related terms
Cold heading
Forming bolt and screw heads from wire at room temperature by striking it in dies at high production rates.
Header
The machine that cold heads fasteners, feeding wire, cutting blanks and striking them in a series of dies.
Head burst
A split on the edge of a cold-headed bolt head, caused by metal being stretched past its ductility.