1. What is Press Tonnage for Blanking?

Definition: This calculator determines the force required to punch or blank a material based on its perimeter, thickness, and shear strength.

Purpose: It helps manufacturers select appropriate press equipment and ensure successful blanking operations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( T \) — Required tonnage (tons)
• \( P \) — Perimeter of blank (inches)
• \( t \) — Material thickness (inches)
• \( S \) — Shear strength of material (psi)

Explanation: The formula calculates the total cutting force needed by considering the length of cut, material thickness, and material strength.

3. Importance of Tonnage Calculation

Details: Accurate tonnage calculation prevents press overloading, ensures clean cuts, and extends tool life by using appropriate force.

4. Using the Calculator

Tips: Enter the blank perimeter (total cut length), material thickness, and shear strength (default 45,000 psi for mild steel). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical shear strength for common metals?
A: Mild steel: ~45,000 psi, Aluminum: ~25,000 psi, Stainless steel: ~65,000 psi.

Q2: How do I calculate perimeter for complex shapes?
A: Sum all straight segments and curved sections (π × diameter for circles).

Q3: Should I add a safety factor?
A: Yes, typically add 20-30% to account for tool wear and material variations.

Q4: What if my material has different shear strength?
A: Use material-specific data sheets or consult your supplier for exact values.

Q5: How does material thickness affect tonnage?
A: Tonnage increases linearly with thickness - double the thickness doubles the required tonnage.