HRA & HRC - does anyone use separate indenters?

[dbooker630]

I recently had one of my hardness testers repaired and recalibrated. The service person told me that it is now recommended to use an individual HRA or HRC indenter instead of the combination HRC indenter being used for HRC, HRA, and HRD scales.

I searched ASTM E18-17e1 for such recommendation and did not see anything specific unless I missed something. I don't yet have E18-19 so I cannot confirm if this is something new.

I would be interested in how my fellow metallurgists approach this and if you have supporting references - thanks!

 

I don't see a reason why you cannot use the same indenter with different loads.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[EdStainless]

You can use the same, but we don't.
This dates back to when we used one that was carbide and one that was steel.
Even though today they are both carbide we still swap them.

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P.E. Metallurgy, Plymouth Tube

 

[MagBen]

Regarding indenter, E18-19 is no much different from -17, except in -19, the tolerances for the geometric features of the Class A and
Reference diamond indenters have been temporarily widened.
We use the same diamond indenter for HRA, C, D as well as superficial 15,30,45N, really no need to have separated ones. There does exist 3 different classes, class B, A and Reference. class A used to calibrate B, Reference used to calibrate A. but they are not for different scales.
WC Ball indenters do have different sizes for different scales 1/16, 1/8, 1/4, 1/2 ''

 

[EdStainless]

We also use different diamond indenters.
We use one for C, and another for the superficial ranges.
It is mostly related to calibration records and not the physical requirements of the test.

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P.E. Metallurgy, Plymouth Tube

 

[dbooker630]

Thanks! I will continue to use a C diamond for HRC & HRA along with an N diamond for the superficial scales.