Fastener screws need to undergo some inspections before or after production before they can be officially put into use. Therefore, in order to obtain better results for fastener screws, these inspections must be done carefully. China Standard Parts Network According to the summed up experience, we will tell you some inspections about fastener screws, and we will list the following points.
1. Inspection of adhesion strength of fastener screw plating
There are many methods for evaluating the adhesion between the coating and the base metal, usually as follows: 1. Friction and polishing test; 2. File method test; 3. Scratch method; 4. Bending test; 5. Thermal shock test; 6. Extrusion Law.
2. Inspection of corrosion resistance of fastener screw coating
The test methods for coating corrosion resistance 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, interleaved corrosion test, etc.
3. fastener screw surface inspection inspection method
There are two types of fastener screw surface inspection, one is the inspection before the screw is electroplated 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 and the surface of the screw is treated. test.
4. Other inspections of fasteners and screws
After the fastener screws are produced and before they are electroplated, we inspect the dimensions, tolerances and other aspects of the screws. See if it meets national standards or customer requirements. After the surface treatment of the screws, we inspect the electroplated screws, mainly to inspect the color of the electroplating and whether there are any broken screws.
