Sheet stretch forming is a manufacturing process used to shape sheet metal into complex curved parts, often for aerospace applications. Here’s how it works:

1. Clamping: A sheet of metal is securely clamped along its edges.
2. Tension: Hydraulic rams pull on the clamps, stretching the sheet of metal beyond its yield point (where it would normally deform permanently).
3. Forming: While stretched, the metal is lowered and pressed over a specially shaped die or form block. The combination of tension and pressing forces the metal to take the shape of the die.

Sheet Stretch Forming Machines Specialized presses are used to perform the stretch forming process.

Sheet Stretch Forming Machine

Key features

• Powerful Rams: High tonnage hydraulic rams provide the immense stretching force.
• Die Table: A table to securely mount the form blocks/dies.
• Jaws: Clamping jaws that grip the sheet metal edges.
• Computer Controls: Modern machines use CNC (Computer Numerical Control) for precision.

Benefits of Sheet Stretch Forming

• Complex Shapes: Stretch forming can create parts with compound curves not easily achievable with other methods.
• Large Parts: Ideal for large aerospace components like wing skins and fuselage panels.
• Strength: The stretching process can increase the strength of the formed part.
• Minimal Springback: The process helps minimize the tendency of the metal to return to its original shape after forming.