METHOD OF ROD-SHAPED THREAD FASTENERS PLASTIC PROPERTIES DETERMINING Russian patent published in 2017 - IPC G01N3/28 

FIELD: testing equipment.

SUBSTANCE: full-size sample of the product in the form of a bolt, screw or stud is stretched by coaxial loading, the values of deformation are measured by which the characteristics values are calculated and the product plastic properties are judged. Loading of the sample is carried out to the maximum load and the test is interrupted after it has been reached, followed by unloading the sample and value recording of its absolute residual elongation, and then calculating the relative uniform elongation (δ_P). The thread of the product is used directly as a design section with markings.

EFFECT: simplification of the test process, enabling the determination of a particularly important plasticity characteristic - relative uniform elongation, improving the accuracy and reliability of measuring the residual plastic deformation of the fastener after exposure to the maximum tensile axial load or in the fracture zone after rupture.

2 cl, 1 tbl, 3 dwg