1. Material Preparation

• Select a ductile sheet metal specimen of specified thickness (e.g., aluminium, steel, or titanium).
• Clean the surface to remove contaminants such as oil, dust, and oxides.
• Ensure the sheet is free from scratches, dents, or pre-existing deformation.

2. Form Die Setup

• Mount the stretch form block (STFB) securely on the press table.
• Verify proper alignment of the die relative to the gripping jaws.
• Ensure the die surface is smooth and free from irregularities.

3. Sheet Positioning and Alignment

• Place the sheet metal between the gripping jaws of the stretch press.
• Align the sheet so that its longitudinal axis is perpendicular to the jaws and centered over the die.
• Confirm that the sheet lies flat without initial curvature.

4. Clamping the Specimen

• Engage the gripping jaws to clamp the sheet along its edges.
• Apply uniform clamping pressure to avoid slippage during stretching.
• Ensure the clamping force is suitable for the material thickness.

5. Initial Pre-Stretch Application

• Activate the hydraulic or pneumatic system to apply a controlled pre-stretch.
• This step eliminates slack and stabilizes the sheet for uniform loading.
• Check for any early signs of wrinkling or uneven tension.

6. Controlled Stretching of the Sheet

• Gradually increase tensile force by pulling the jaws outward at a regulated rate.
• Maintain symmetrical stretching for uniform strain distribution.
• Continuously monitor elongation and force to avoid localized thinning.

7. Forming Phase (Wrapping Over the Die)

• Simultaneously raise the form die (vertical press) or wrap the sheet around the die (horizontal press).
• Coordinate die displacement with jaw movement to maintain tensile stress.
• Allow the sheet to plastically deform and conform to the die geometry.

8. Achievement of Final Contour

• Continue stretching until the sheet fully matches the die profile.
• Maintain the tensile load briefly to stabilize the deformation.
• Reduce chances of elastic springback by holding the load momentarily.

9. Release of Tensile Load

• Gradually decrease hydraulic or pneumatic pressure to release tension.
• Retract the jaws slowly and return the die to its starting position.
• Avoid sudden unloading to minimize springback effects.

10. Part Removal

• Open the gripping jaws and carefully remove the formed component.
• Handle the part gently to preserve the newly formed contour.

11. Inspection and Evaluation

• Examine the part for dimensional accuracy and surface quality.
• Check for defects such as cracking, wrinkling, rippling, or excessive thinning.
• Measure final thickness, curvature, and strain distribution.

12. Documentation

• Record material specifications, forces applied, displacement values, and observed deformation.
• Note any defects, measurements, and final shape details for analysis.