The elastic rebound hardness test instrument is called Shore hardness tester and Richter hardness tester. The hardness values measured are called Shore hardness and Richter hardness respectively, and expressed by HS and HL.The principle of Shore hardness tester test is to drop the diamond punch of specified shape on the sample surface from a fixed height H, and the punch is bounced up to a certain height H.The harder the forgings, the higher the jump height h value, so the ratio of H and HO, and then multiplied by the specified coefficient K as shore hardness value, that is, hs-K (H/HO)GB4341 -- 84 provisions, the expression of Shore hardness value, first write the value, value marked with HS, and finally on behalf of the type of hardness meter symbol.
 

Shore hardness tester is very light in weight, the standard is 4kg, can be directly placed on the forgings test, mostly used for large forgings.When the forging surface is curved, the radius of curvature should not be less than 32mm.

The hardness value measured by the pressing method mainly reflects the ability of the forging surface to resist the plastic deformation caused by another object.Forgings of iron and steel material hardness measured by pressing method and its strength have an approximate conversion relationship, which is the main reason for the use of pressing method.
 

Brinell hardness tester uses a large indenter to measure the hardness of forgings with low hardness, as well as the hardness of multiphase metals composed of several phases with widely different hardness.Rockwell hardness tester uses two different indenter, which can test soft metal or hard metal. It has strong adaptability and is necessary equipment in heat treatment workshop of forging works.