What inspections are required for fasteners?


Fastener screws need to be inspected before or after pr […]

Fastener screws need to be inspected before or after production before they can be officially put into use. Therefore, in order to obtain better results of fastener screws, these inspections must be carried out carefully and based on the summary of experience. To tell you about some inspections of fasteners and screws, we list the following points:

1. Inspection of the adhesion strength of the fastener screw coating
There are many methods to evaluate the adhesion of the coating to the base metal, usually the following: friction polishing test; 2. file method test; 3. scratch method; 4. bending test; 5. thermal shock test; 6. extrusion method.

2. Corrosion resistance inspection of fastener screw plating
The corrosion resistance inspection methods of the coating include: atmospheric exposure test; neutral salt spray test (NSS test); acetic acid salt spray test (ASS test), copper accelerated acetic acid salt spray test (CASS test); and corrosion paste corrosion test (CORR test) and solution spot corrosion test; immersion test, inter-immersion corrosion test and so on.

3. fastener screw surface inspection method
There are two types of fastener screw surface inspection, one is the inspection before the screw is produced after the screw is produced, and the other is the inspection after the screw is electroplated, that is to say, after the screw is hardened, the surface of the screw is processed. test.

4. other inspections of fasteners and screws
We inspect the dimensions and tolerances of the screws before they are plated after they are produced. See if it meets industry standards or customer requirements. After the surface treatment of the screws, the screws we have plated are inspected, mainly to check the color of the plating and whether there are broken screws.

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