What exactly is the inspection of riveting screws? Recently it was seen that someone was asking this question, so for everyone to briefly introduce the situation in this regard, inspection pressure riveting screws are divided into two kinds, one is the production of riveting screws After the electroplating before the test, the other is the test after the screw plating, that is to say, after the screws are hardened, the screw surface after the test. Before the pressure riveting screws are produced and not plated, we carry out inspections on the dimensions, tolerances and other aspects of the screws. See if you meet national standards or customer requirements. After the surface treatment of the screws, we have inspected the electroplated screws to check the color of the plating and whether there are any broken screws. In this way, when we send the screw cargo to the customer, the customer can smoothly pass the goods when they receive the goods.
Appearance quality requirements
The inspection of the appearance of the pressure riveting screws is performed from various aspects such as the appearance and the plating layer.
Screw plating thickness test
1, measuring method
The use of a micrometer, vernier caliper, plug gauge and so on.
2, magnetic method
The magnetic method for measuring the thickness of the coating is a non-destructive measurement of the non-magnetic coating on the magnetic substrate with a magnetic thickness gauge.
3, microscopy
Microscopy is known as metallography, where the etched fasteners are magnified on a metallurgical microscope with micrometer eyepieces to measure the thickness of the coating on the section.
4, timing fluid method
The chronofluidic flow method uses a solution that causes the dissolved coating solution to flow on the partial surface of the coating, and the thickness of the coating is calculated based on the time required for the partial coating to be dissolved. There are plating drop method, anodizing Coulomb method and so on.
Screw Plating Adhesion Strength Test
Fastener manufacturers have many methods for assessing the adhesion of the coating to the base metal, usually in the following ways.
1, friction polishing test; 2, boring knife method test; 3, scratch method; 4, bending test; 5, thermal shock test; 6, extrusion method.
Corrosion test of screw plating
The test methods for the plating corrosion resistance of fastener manufacturers include: atmospheric explosion test; neutral salt spray test (NSS test); acetate spray test (ASS test), copper accelerated acetate spray test (CASS test); and Corrosion Corrosion Test (CORR Test) and Solution Droplet Corrosion Test; Immersion Test, Intermittent Corrosion Test, etc.