Screw hardness, mainly refers to the surface hardness of the screw. The hardness of bolts, screws and studs shall be measured at the head, end or rod.Hardness value refers to the test data corresponding to the ability of a material to resist local hard objects pressing into its surface. According to the different hardness tester, the value is different.The commonly used hardness values are Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV). The conversion relationship between the three hardness values is HRC = Hb / 10hrc = 100-37353 / (HV + 200)Nork quality laboratory is equipped with three Vickers hardness tester and Rockwell hardness tester, covering the hardness testing of all fastener products of the company.
Tensile test is a test method to determine the properties of materials under axial tensile load.The elastic limit, elongation, elastic modulus, proportional limit, area reduction, tensile strength, yield point, yield strength and other tensile properties of materials can be determined by using the data obtained from tensile test.
Metallographic analysis is an important means of experimental research on metal materialsMetallographic microscope can be used to inspect the microstructure defects of raw materials, the depth of decarburized layer / carburized hardened layer, and the thickness of coating layer;
Measure the breaking torque of bolt or screwThe test bolt or screw is clamped in the test device, and its failure torque is measured.During the test, the bolt or screw shall only bear the torque, and the specimen shall not break until the minimum failure torque is reached.During the test, there should be no friction between the head and thread of bolt or screw, which will affect the test results.
Thread accuracy detection: thread ring gauge, thread plug gauge, triangle tooth screw triangle micrometer detectionGroove detection: groove plug gaugeDimensional tolerance, geometric tolerance detection: caliper, micrometer, two dimensional, projector
The purpose of salt spray test is to evaluate the salt spray corrosion resistance of coating or coating of fastener products.