Forming:
A progressive die can control an inside radius but cannot control
an outside radius. Similarly, the die can control dimensions to
the inside of a bend but not to the outside.
To avoid hole deformation, leave at
least three times the material thickness from the form tangency
to the edge of the hole.
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Forming an undercut can eliminate
the need for a formed sharp corner. The tooling cost is the same;
however, the undercut die will hold up bet-ter than the sharp
corner die, thereby reducing downtime.
An improperly
designed bend radius can cause fractures in the bend area.
General Rule #3:
The radius of a bend should be a minimum of 1.5 x the material
thickness. |
Angular Form Tolerances:
90° ± 2°
1 Form Station
Not many tool adjustments
90° ± 1°
1 Form Station
1 form qualifier or cam (50 tooling hours) and some tool adjustments.
90° ± ½°
1 Form Station
1 form qualifier or cam (50 tooling hours) and many tool adjustments.
To form beyond 90° in one station, add a
gusset
It is preferred to eliminate lancing by blanking
around a tab before forming. The cutout should extend a minimum
of .030 beyond the bend line.
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