Hole Expansion Ratio (HER) Punching Setup

This is a mechanical setup designed to adapt to universal load frames and hydraulic presses in order to enable punching the 10mm hole needed for subsequent Hole Expansion Ratio (HER) testing of sheet metal samples. This is a complete kit that encompasses the die set assembly, the punches, as well as a wide array of custom precision punching dies to meet a wide range of clearances (5-25%) for sheets ranging in thickness between 0.6mm and 5mm. This setup enables precision hole punching (critical for successful HER testing) and allows for total independence from the HER testing machine (no need to swab setups – critical for meeting short punch-to-test times).

General Specifications:

  • Adaptability: Most universal load frames (50kN or higher) are equipped with compression platens (INSTRON, ZwickRoell, MTS, etc.) as well as most hydraulic presses (manual or servo presses)
  • Max. Punching Force: ~100kN
  • Max. Sheet Thickness:~5mm
  • Max. Punching Speed: ~100 mm/s
  • Punching Direction: Compression
  • Gripping:
    • Manual: 20kN


  • Very economical and enables the utilization of existing load frames
  • Self-centering design to protect the punch from side loading during operation
  • Can accommodate sheet samples with different thicknesses (~0.6mm to ~5mm)
  • Can achieve a wide range of clearances (~5 to 25%) for all sheet thicknesses, and with small step sizes (down to 0.03mm between any successive dies)
  • Easy replacement of consumables (punches and punching dies)

HER Punching Setup in Use: