How is the hardness of stainless steel threaded fittings measured?

How is the hardness of stainless steel threaded fittings measured?

Stainless steel threaded fittings are generally measured by three hardness indicators:Brinell,Rockwell,and Vickers.

Vickers hardness

The Vickers hardness test for stainless steel threaded fittings is also an indentation test method that can be used to determine the hardness of very thin metal materials and surface layers.It has the main advantages of the Brinell and Rockwell methods,while overcoming their basic disadvantages,but it is not as simple as the Rockwell method,and the Vickers method is rarely used in steel pipe standards.

Rockwell hardness

The Rockwell hardness test for stainless steel threaded fittings,like the Brinell hardness test,is an indentation test method.Differently,it measures the depth of the indentation.The Rockwell hardness test is currently widely used,with HRC being second only to Brinell hardness HB in steel pipe standards.

Brinell hardness

In the standard for stainless steel threaded fittings,Brinell hardness is widely used and is often represented by the indentation diameter to indicate the hardness of the material,which is both intuitive and convenient.But it is not suitable for steel pipes made of harder or thinner steel.

Hardness testing

The W-B75 Vickers hardness tester can be used for annealed stainless steel threaded pipe fittings with an inner diameter of 6.0mm or more and a wall thickness of 13mm or less.It is very fast and easy to test,and is suitable for rapid and non-destructive qualification inspection of stainless steel threaded pipe fittings.Stainless steel threaded fittings with an inner diameter greater than 30mm and a wall thickness greater than 1.2mm shall be tested for HRB and HRC hardness using a Rockwell hardness tester.Stainless steel threaded fittings with an inner diameter greater than 30mm and a wall thickness less than 1.2mm shall be tested for HRT or HRN hardness using a surface Rockwell hardness tester.Stainless steel threaded fittings with inner diameters less than 0mm and greater than 4.8mm shall be tested for HR15T hardness using a specialized Rockwell hardness tester for pipes.When the inner diameter of stainless steel threaded fittings is greater than 26mm,the hardness of the inner wall of the pipe can also be tested using a Rockwell or surface Rockwell hardness tester.