Industrial Nut Surfaces Inspection

　There are two kinds of industrial nut surface inspection, one is the inspection of industrial nuts after plating, that is, industrial nuts after hardening, industrial nuts after surface treatment inspection. The other is the inspection of industrial nuts after production and before plating. The industrial nuts are inspected for dimensions, tolerances, etc. before plating after production. See if it meets national standards or customer requirements. After the surface treatment of industrial nuts, we inspect the plated industrial nuts, mainly to check the color of the plating and the presence of bad industrial nuts. This way, when we send industrial nuts to our customers, they will be able to pass through customs smoothly when they receive them. Inspection after industrial nut treatment.

　　I. Appearance and quality requirements

　　The inspection of the appearance of industrial nuts is carried out from various aspects such as appearance and plating.

　　II. Test of adhesion strength of industrial nut coating

　　There are many ways to judge the adhesion of the coating to the substrate metal, usually the following.

　　1, friction polishing test; 2, file method test; 3, scratch method; 4, bending test; 5, thermal shock test; 6, extrusion method.

　　III. Inspection of the coating thickness of industrial nuts

　　1、Measurement method

　　The amount used is a micrometer, vernier caliper, plug to gauge, etc.

　　2、Magnetic method

　　The magnetic method is a non-destructive measurement of the non-magnetic coating layer on a magnetic substrate using a magnetic thickness gauge.

　　3、Microscopic method

　　The microscopic method is called the metallographic method, which measures the thickness of the coating on a section by placing an etched fastener on a metallographic microscope with a micrometer for magnification.

　　4. Timed flow method

　　The timed flow method is to calculate the thickness of the coating by injecting a stream of solution that can dissolve the coating onto the local surface of the coating, based on the time required for the local coating to be dissolved. There is also the coating drip method, anodic dissolution coulomb method, etc.