long thread shoulder screw test method?

Since ancient times, no matter what we buy, there is a step of inspection, to ensure that no goods wrong plate. The same is true of screws and fasteners, so what is the test method for long thread shoulder screw?

One is to check the appearance of the long thread shoulder screw first. Want to see the surface of the screw there are potholes, or obvious burr, poor electroplating and so on.

Two is to check the size of the screw. Micrometer and vernier caliper should be used when measuring the size of the head and thread. Ruler and tape should not be used. Because using a ruler or tape measure can cause a lot of errors. However, if the screw length is too long, you will need to use a ruler or tape measure when measuring the length. Because the length is very long, the tolerance is generally very large, there will be no error when using the ruler, tape measurement.

Three are to check the electroplating conditions of long thread shoulder screw. Some customers for the screw plating thickness is generally required, such as coating thickness at least 6 m or 8 m, etc. If the coating thickness does not meet the requirements, it will easily cause damage to the accessories. Sometimes not only to check the thickness of the screw coating, but also need to check the adhesion of the screw electroplating. If the electroplating adhesion is not strong enough, it will easily cause the screw surface to fall off, the screw will also be easy to rust, will affect the appearance of the product.