Screw pull-out force testing machineIt is a specialized testing equipment used to evaluate the pull-out resistance of fasteners such as screws, bolts, and expansion screws. Its core functions include measuring mechanical properties such as ultimate tensile strength, yield strength, and failure load.
Preparation before operation:
Equipment inspection:
Confirm that the host, fixtures, and sensors are intact, check the sealing of the oil cylinder or motor system to avoid leaks.
Connect the power supply (220V voltage), preheat the device for 5-10 minutes, and ensure that the display screen has no abnormal alarms.
After the equipment is preheated, the force value display needs to be reset (press the reset button) to eliminate the initial error.
Sample and fixture installation:
The surface of the sample is clean and free of oil stains, with a weight deviation of ≤ 20g, to avoid eccentric loading.
Secure the screw to a specialized fixture (such as a customized pull-out fixture for expansion screws), ensuring vertical alignment with the loading direction, and tighten the fixing screw to prevent sliding.
The substrate (such as concrete or wood) needs to be pre drilled and rigidly fixed to the test bench.
Core operating steps:
Parameter settings:
Set the loading rate (usually 2-5mm/min), target load (such as 1.1-1.3 times the design value), and shutdown conditions (such as fracture detection or displacement exceeding the limit) on the control panel.
Enable the peak recording function (press the peak button) to monitor the force displacement curve in real-time.
Perform testing:
Start the device, slowly apply tension (rotate the valve or click the run button), and observe real-time data.
When the screw is pulled out or broken, the equipment automatically records the peak pulling force (P value) and saves the curve data after stopping the machine.
One person is required to support the equipment during testing to prevent accidents caused by oil pump falling or screw breakage.
End processing:
When unloading, loosen the exhaust valve counterclockwise to relieve pressure, and remove the sample to check the failure mode (such as thread slippage or substrate damage).
Turn off the power, clean the chamber and fixture residue, and wipe the contaminated area with 70% alcohol.