DETERMINING HARDENING DEPTHS
In our industrial laboratories hardening depths are determined according to CHD or NHT.
Determining CHD
The specification of the case hardening depth consists of the short letter CHD and the reference depth of the insert in mm. If a limit hardness other than 550 HV1 or a test force other than HV1 is used, this must be indicated after the short code CHD.
Determining NHT
The specification of the nitriding depth is composed of the shortcut Nht with the numerical value of the limiting hardness (= measured core hardness + 50 HV, as a rule in HV0.5) and the amount of nitrating hardness depth in mm. If a test force other than HV0.5 or a different limiting hardness is used, this should be indicated after the short code Nht.