Inspection References at Each Stamping Stage

Sheet Metal Stamping Process Examples

Following a stamped bracket through blanking, piercing and forming, with inspection requirements defined at each stage.

Product Overview

A stamped sheet-metal component may require several operations before reaching its final shape.

Blanking establishes the outer profile, piercing creates internal openings, and forming produces bends or other three-dimensional features.

The sequence depends on part design, material and tooling approach.

Blanking produces the required sheet-metal outline.
The retained blank is checked against the applicable flat-pattern requirements, including designated edges and overall geometry.
Material thickness, edge quality and blank dimensions are considered according to the drawing.

Piercing produces required openings in the sheet metal.
Hole dimensions and positions may be evaluated from flat-pattern references before forming.
Where piercing is performed at another stage, the applicable inspection references must correspond to that operation.
Forming creates flanges, bends and other required features.
The finished component is inspected using the datum and support conditions defined on its approved drawing.
Bend angle, flange height and hole relationships may require verification after forming.

If a hole meets its flat-stage requirement but fails the finished-part requirement, the forming operation or inspection reference may require further review.
Depending on geometry and tooling access, an alternative operation sequence may be considered.
A manufacturing change should preserve the finished component's functional requirements.

Retained blank	Identify the outline, flat-view reference edges and edge requirements.
Pierced openings	Confirm hole and slot dimensions, reference edges and the stage at which they are measured.
Formed geometry	Specify the finished-part datum, support condition and any final hole or flange limits.

Record the reference used before forming and check the finished part in its specified setup.

If a hole passes the flat check and fails after forming, review the reference, tool access and support before evaluating a different sequence.

Send the finished-part drawing, sheet specification and expected quantity. Include the flat pattern and any critical formed features if available.