When it comes to performance applications in the automotive domain, fasteners are one of the most vital elements required for the functioning of a device. The fasteners are defined as the crucial tools that help join to or more different parts of the bigger device. Thus, by no means can the fastener be an unreliable source. To avoid fastener failures at all costs, a series of different tests assessing the various features of fasteners like the tensile strength, rotational capacity, torque-tension, stress-durability, and stress-rupture are checked before they are introduced into the market.
Wide classification of fasteners
The fasteners are divided into three categories; screws, bolts, and studs. All three of them play a part in permanently or temporarily joining two parts of a device. Before a fastener comes into action, it is important to understand its concerns and limitations to always avoid unfavorable results, right?
Tests for checking the quality of the fasteners
The manufacturing process of a fastener includes heat treatment of the raw materials. This treatment can change the overall testing results of the tool. This is why; it is advised to test the raw materials that are being used for making the fasteners first and then the final product. The main things that are tested include the mechanical strength and the dimensional analysis of the fastener. Almost every fastener developing industry abides by a strict testing checklist for their products and so do the emerging GLSfastener developers.
Here are a few essential tests for this hardware:
Salt-spray fog test: This test is done to check the corrosion of the fastener. The spray is done and the number of hours is observed before the white or red rust appears on the hardware.
Chemical composition: Before the heat treatment, it is better to check the list of major and trace elements that are going to be used to make the fasteners.
Hydrogen embrittlement: also known as stress durability, is also tested for the internal thread fasteners.
Mechanical testing: The mechanical testing domain of the fastener hardware is a broad one. It requires testing of the product to showcase its suitability for the desired application. The mechanical properties are related to the elastic and inelastic behavior of the tool when the force is applied. It is based on the relationship between stress and strain. Major mechanical properties that are tested include:
Tensile strength: The tensile testing apparatus determines the force that would be required to remove the screw, bolt, or stud from the base material it is fitted into. The results vary for each fastener owing to the different shapes and sizes of the tool.
Torque-tension: In this type of testing, the amount of tightening torque required is determined. We can also find out the nut factor and the overall coefficient of friction through torque testing as well.
Stress rupture: The manufacturers of fasteners conduct this test to assess the performance of their tool under constant load at different temperatures.
Vibration test: This test is done to find out the life span of the hardware tool and see its self-loosening characteristics under vibratory conditions. Using the Junker machine, a preload-decay graph can be obtained which is highly useful to decide fasteners’ quality.
Hardness test: If you want to determine the core hardness of the fastener to assess the durability or wear of the tool, you can carry out the hardness test for your required results.
In the end
This is the list of some specific and non-specific tests that are done to check the quality of the fasteners. It is safe to say that most of the fastener developers go through a thorough checklist to ensure that high-quality products are introduced to the market.