Fastener screw production inspection

- Dec 08, 2020-

Does the production of fasteners and screws require certain inspections?

Fastener screws need to be inspected before or after production before they can be officially put into use. Therefore, in order to get better results of fastener screws, you must be careful when performing these inspections. Let me introduce you Some inspection points about fasteners and screws.


  Fastener screws need to pass inspection

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    01   Inspection of adhesion strength of fastener screw coating

    There are many ways to evaluate the adhesion of the coating to the base metal, usually the following:

    Friction polishing test;

    Scratch method

    Bending test;

    Thermal shock test

    Extrusion method.


    02  Corrosion resistance inspection of fastener screw plating

    The coating corrosion test methods 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, etc.


    03  Fastener screw surface inspection method

   There are two types of fastener screw surface inspection, one is the inspection after the screw is produced before it is electroplated, 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 treated. test.


    04  Fastener and screw other inspection

    We inspect the dimensions and tolerances of the screws before they are electroplated. See if it meets national 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.