Destructive Testing 101
The Importance of Destructive Testing
& Performing Tests in the Shop.
With the advanced materials being used during vehicle production such as HSS and UHSS, destructive testing is a must in the collision repair industry to ensure proper and safe repairs.
Whether we are using Resistance Spot Welding or MIG/Mag welding, we must perform a destructive test before welding on the actual application. This helps ensure that the weld settings are correct and the welder is functioning properly.
How to Perform a Destructive Test:
In the shop, we have two destructive tests: Twist Test and Peel Test. Which test is best to perform depends on the type of weld being done and the material used.
The Peel Test is best performed on a resistance spot weld (see image below).
- This test done by clamping the test material in the vice and peeling the top layer from bottom using rounded end channel locks.
- With this test we should see the weld nugget stay in tact while tearing a hole in one of the layers.
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| The "Twist test" uses a vice and a hammer. Using the hammer hit up and down on sample "twisting" the weld until it comes apart. |
- NOTE: This test may be harder to complete on HSS and UHSS
The Twist Test this can be done on resistance spot welds or plug welds.
- This test is performed by clamping one layer in the vice and twisting top layer from bottom.
- Using the hammer hit up and down on sample "twisting" the weld until it comes apart.
- With this test we should tear a hole from one of the layers for a successful test.
- NOTE: According to I-CAR standards: On an 8mm Plug Weld, a 5-10mm hole should tear out from bottom coupon depending on the material and stack up.
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