βš™οΈ Sheet Metal Design

Punch & Die Design Calculator

Clearance Β· Cutting Force Β· Stripper Force Β· Press Tonnage Β· Punch & Die Sizes

πŸ”² Blanking
β­• Piercing
πŸ“ Notching
mm
mm
%
Soft Al: 3–8% Β· MS: 5–8% Β· SS: 6–10%
pcs
Die Clearance (per side)
-mm
Total gap =, mm
Cutting / Blanking Force
-kN
F = 0.8 Γ— UTS Γ— t Γ— Perimeter
Stripper Force
-
kN (β‰ˆ15% of F)
Press Tonnage
-
Tons
Punch Size
-
mm
Die Size
-
mm
Part / Blank
-
mm
Perimeter
-
mm
Design Summary
Operation-
Material UTS-
Shear Strength-
t Γ— Perimeter-
Safety Factor1.25Γ—
Blanking: Punch = Part βˆ’ 2c Β· Die = Part size
Piercing: Die = Hole size Β· Punch = Hole βˆ’ 2c

Punch & Die Design Calculator: Sheet Metal Tooling Guide

Punch and die tooling is the heart of sheet metal blanking, piercing and forming operations. Correct clearance, cutting force and tonnage calculation are critical for tool life, part quality and press selection. This calculator follows AIDA, Schuler and standard press tooling guidelines.

πŸ“‹ How to Use This Calculator

  1. Select operation type, Blanking, Piercing, Notching or Trimming.
  2. Enter material type and thickness (mm).
  3. Specify blank shape and dimensions (perimeter in mm).
  4. View die clearance percentage, cutting force, stripping force, tonnage and spring travel results.

πŸ“ Formula & Working Principle

Cutting Force F = L Γ— t Γ— Ο„_shear. Ο„_shear = 0.7 Γ— UTS. Die Clearance c = k Γ— t (k=0.05–0.08 per side for steel). Stripping Force = 2–20% of cutting force. Punch penetration = 0.3–0.5t.

πŸ’‘ Worked Example

Blank: 100Γ—100 mm square, CRCA steel, t=2 mm, UTS=400 MPa. Perimeter L=400 mm. Cutting Force = 400Γ—2Γ—0.7Γ—400 = 224,000 N = 224 kN. Die clearance = 0.06Γ—2 = 0.12 mm per side.

❓ Frequently Asked Questions (FAQ)

Q: What happens when die clearance is too large?

Excessive clearance causes burr, material rollover and poor cut quality. Too little clearance results in high cutting force, tool breakage and secondary shear. Correct clearance depends on material type and thickness.

Q: What punch materials are used?

D2 tool steel (HRC 58–62): general purpose. M2 HSS: high production, abrasive materials. Tungsten carbide: highest volume, abrasive materials, longest life.

Q: What safety factor should be used for press tonnage?

Select a press with 1.5Γ— the calculated tonnage. Exceeding press capacity risks press damage, die breakage and safety hazards.

Q: When is a stripper plate necessary?

For thin materials (t<3 mm), deep piercing, small punches and high-speed pressing, a stripper plate is essential to cleanly strip material from the punch.

Q: How can scrap skeleton be minimised?

Use optimised nesting software. For circular blanks, use hexagonal close-packing layout. Good nesting can achieve 75–85% material utilisation.