Everyone is familiar with the tension test of bolts. The wedge load test that bolts need to do may be unfamiliar. In fact, both tests are completed by universal testing machine.
Here is a detailed introduction to wedge load test and its difference from tensile test.
First of all, we will introduce what is wedge load test. Load test uses gaskets with a certain angle to pull bolts. It is called load test mainly because products such as fasteners are used to fix things.
The fasteners are not always vertical when they are fixed, and may present different angles, and the mechanical properties of different angles are equally important to users.
The difference between the tensile test and the tensile test is that the tensile test refers to the mechanical properties of the bolts in the vertical state to judge whether they are qualified or not, while the load test refers to the tensile properties of gaskets with a certain angle.
Usually the bolts below M20 are wedged at 6 and 10 degrees, and above M20 are wedged at 4 and 10 degrees.
Next, we will introduce the wedge load test method. In wedge load test, wedge blocks with different angles are usually placed under the bolt head (clamp body). During the test, the pull rod of clamp body is clamped into the round clamp of universal testing machine and fixed well.
Then the tensile test was carried out to know the fracture of the specimen, and the test load was recorded. Special attention should be paid here to observe the specific location of the break when the bolt breaks. The test of the sample breaking in the length of the rod or the unscrewed thread is qualified.
However, for full-threaded bolts or bolts, such as those that break the unscrewed part of the thread, the specimen is also qualified even if it extends or extends to the fillet or head under the head before breaking.