The non-standard screw industry will test the products produced, such as special-shaped screws, non-standard screws and so on. After testing, we will find out where the product is not qualified, and then better improve our product. Only in this way can we provide customers with better quality products and win the favor of users.

Testing of non-standard screws in fasteners, appearance and quality requirements; appearance inspection of non-standard screws, inspection of electroplating layers. The thickness inspection of the screw coating can be carried out with a micrometer, a vernier caliper, a plug gauge, etc. Magnetic method The magnetic method is used to measure the thickness of the coating layer, which is a non-destructive measurement of the non-magnetic coating layer on the magnetic substrate with a magnetic thickness gauge. Magnify on a metallographic microscope with a micrometer eyepiece, and measure the thickness of the coating on the cross-section; time flow method.

The timing liquid flow method uses a solution that can dissolve the coating to flow on the local surface of the coating, and calculates the thickness of the coating according to the time required for the local coating to dissolve. There are also coating drop method, anodic dissolution Coulomb method, etc. Inspection of adhesion strength of screw coating: There are many methods for evaluating the adhesion between the coating and the base metal, usually including the following: friction polishing test; file method test; scratch method; bending test; thermal shock test; extrusion method. Inspection of corrosion resistance of stainless steel screw coating: the inspection methods of coating corrosion resistance are: atmospheric exposure test; neutral salt spray test (NSS test); acetate salt spray test (ASS test), copper accelerated acetate salt spray test (CASS) test); and corrosion paste corrosion test (CORR test) and solution spot corrosion test; immersion test, inter-dipping corrosion test, etc.