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Direct Verification of Hardness Testers: Rockwell, Micro, & Brinell

As some of you might be aware Nadcap has put out Auditor Advisory (HT – 2018 – 002) on March 14, 2018.  In this advisory it addresses Direct Verification of Rockwell, Micro, & Brinell Hardness Testers. 


After reviewing the advisory it is clear that Nadcap will and has started requiring accredited Heat Treaters to have their hardness testers Directly Verified.  So, how might this impact you?    Impacts could be receiving a corrective action, loss of accreditation, down time, recalls, etc…


Machines made before 2007 might or might not have had been made with a Direct Verification being performed.   It is my understanding that older Rockwell Testers will probably not pass a Direct Verification.  Therefore, the tester must be overhauled, if possible, in hopes that once it passes Direct Verification that it still passes Indirect Verification.  


Who can perform accredited Direct Verification’s?  Most manufactures of hardness testers today are accredited to perform Direct Verifications.  That being said most manufacturers will only work on their equipment.   Some manufacturers will only work on/support testers from a certain number of years ago.  Others will not perform direct verification once they are in the field.  I only know of 1 manufacturer in the country that will work on other manufacturer’s equipment.  Most accredited calibration houses that are capable of performing Indirect Verifications are not accredited for Direct Verifications.  I believe this is mainly due to the costs associated with becoming accredited for Direct Verification since it is only required at the time of manufacture, overhaul, or when it fails an Indirect Verification.


Although the ASTM standards allow Direct Verifications to be performed on the customer site, it is not common to do so.  Most of the time Rockwell & Micro hardness testers are shipped to the manufacturer to be certified.  This process is both costly and time consuming causing the customer will be without their tester for weeks or months.


Prices to have a tester looked at and possibly directly verified range from many hundreds of dollars to many thousands of dollars.  There is no guarantee that once a company is hired to look at the tester you would like to have directly verified, that the tester will pass.


How are people handling this requirement?  I have spoken to many companies and their opinions and approaches to this advisory vary greatly.  Some people think that this advisory will be revoked.  Others are pairing down the number of testers that they have or use for Nadcap testing.  Others are trying to justify purchasing new testers that come with a Direct Verification.  How you and your company choose to address this is completely up to you.


United Service Company Inc is here to support you the customer.  We are happy to answer any questions that you may have and we currently have both new and reconditioned hardness testers with Direct & Indirect Verifications ready for immediate delivery.


Please feel free to call or email us with any questions that you might have.

Brinell Blocks
Leeb Blocks
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