Screw Withdrawal Force Meter

Screw withdrawal force is an indicator of the strength, density and shear modulus of wood. Therefore, Fakopp Enterprise has developed a portable screw withdrawal force meter. The applied screw diameter is 4mm, the length of the thread is 18 mm. The screw withdrawal force is a local parameter, but selecting a representative location on a beam, it can provide useful information in wooden structure evaluation.

  1. Drive the screw into the wood material, perpendicular to its surface.
  2. Connect the cable of the force transducer to the display unit R320.
  3. Switch on the unit by pressing the “ON” button for 3 seconds.
  4. Select the Peak hold function.
  5. Start the screw withdrawal process by placing the mechanics over the screw. Catch the screw head by the fork of the force transducer.
  6. Slowly turn the handle clockwise until the screw is removed. The speed of the withdrawal should be approximately 0.5 mm/s.
  7. Record the maximal force value and press the “Max” button before the next test to reset the display.
  • Screw withdrawal mechanics with force transducer
  • Display unit, R320
  • Screws and screwdriver
  • Rechargeable battery and charger
  • Aluminium carrying box
  • 10 special screws
  • User manual
Force transducer capacity
5 kN (survives 10kN)
Temperature sensitivity
less than 0.005%/Ko
Hysteresis error
less than 0.05%
Repetition error
less than 0.03%
Operating temperature
-10 °C to +40 °C
350 Ω
Kaliber MM Kft., Budapest, Hungary
Force meter resolution
5 N
Display unit operation temperature
+10 °C to +40 °C
4 pieces of AA size 1.5 V battery