How to check the quality of screws? Screw processing manufacturers have a coup!

Let's learn how to test the quality of screws with the screw processing manufacturer Xiaobian.

1. Appearance quality requirements

The inspection of the appearance of stainless steel screws is carried out from aspects such as appearance and electroplating.

2. Inspection of the thickness of the screw coating

1. Measuring method: The amount used includes micrometer, vernier caliper, plug gauge, etc.

2. Magnetic method: The magnetic method is used to measure the thickness of the coating layer. Non-destructive measurements on non-magnetic coatings.

3. Microscopy: Microscopy is called metallography, which is to etch fasteners, Put it on a metallographic microscope with a micrometer eyepiece to magnify, and measure the thickness of the coating on the section.

4. Time flow method

The timing flow method is to use a solution that can dissolve the coating to flow on the local surface of the coating, according to the local The time required for the coating to dissolve is calculated to calculate the thickness of the coating. There are also coating drop method, anodic dissolution Coulomb method, etc.

3. Inspection of the adhesion strength of screw coating

There are many ways to evaluate the adhesion between the coating and the base metal, usually the following.

1. Friction polishing test;

2. File method test;

3, scratch method;

4. Bending test;

5. Thermal shock test;

6. Extrusion method.