Our company has just found out that ASTM E18 was revised last year. The hardness penetrators/indenters now have to be certified. Does anyone know how to go about certifying the existing indenters we already have or do we need to throw all away and buy new ones with the proper certification? The cost has jumped from $175.00 to $500.00.

What is the best way to control these indenters?

Thank you,
kat.k.

http://www.hardnesstesters.com/astm-e18-rockwell-hardness-testing-method.htm

Is a decent source for information on this...we've always purchased certified indenters and then verified them on two different standard blocks in the ranges/scales they'll be used.

Let me know if that site helps. As a side item I figured I'd mention the issue we ran into. Funny how the simple stuff sneaks by. In our reporting we didn't update the report to reflect the use of tungsten carbide indenters...i.e. we were reporting HB rather than HBW and we received a minor finding for that :rolleyes: if it's not one thing it's another :D

Thank you, Benjimen. I will take a look at this and get back with you.

kat.k.

Let me know if that site helps. As a side item I figured I'd mention the issue we ran into. Funny how the simple stuff sneaks by. In our reporting we didn't update the report to reflect the use of tungsten carbide indenters...i.e. we were reporting HB rather than HBW and we received a minor finding for that if it's not one thing it's another :D

Made me laugh. Our customer rejected a PPAP since we reported HBW not HB. It took a lot of tact to help them realize how long ago that change was made.

Wolframite indeed!

Let me know if that site helps. As a side item I figured I'd mention the issue we ran into. Funny how the simple stuff sneaks by. In our reporting we didn't update the report to reflect the use of tungsten carbide indenters...i.e. we were reporting HB rather than HBW and we received a minor finding for that :rolleyes: if it's not one thing it's another :D

This site has helped a great deal. Thank you, Kat

Hello, it's me again. We just received our first certified indenters. Do we need to control our indenters in our gage system? Do they need to be re-certified at a certain interval? When I looked in the hardness standard, it said to verify under a magnifying glass for chips and cracks. Is this enough for a TS audit? I don't want to get nailed in a TS audit for not calling them back up for calibration. Any suggestions?

Thank you,
Kat.K.

The indenters are verified each time they are used for, and pass an indirect verification of the tester. There is no requirement to recertify them. You will not normally be able to see if they are cracked or chipped, unless you are using high magnification. The usual failure area is the bonding agent between the diamond tip and the carrier. Normally you begin to get erratic readings when that happens.

Regarding control, the -07 version of the standard ties the indenter to a particular machine, i.e. a machine cannot be used unless the indenter has been test block verified with it. See E 18-07 A1.4.10

So, if I can tie the indenter back to the cert to prove they have been certified, I could probaly add to the hardness tester instruction to verify with another indenter if there is any question with the readings? Do you think this would be sufficient? Thanks for your suggestions.

kat.k.

So, if I can tie the indenter back to the cert to prove they have been certified, I could probaly add to the hardness tester instruction to verify with another indenter if there is any question with the readings? Do you think this would be sufficient? Thanks for your suggestions.

Yes, for the indenter. It will have a cert, and it will be serialized.

Before you can use it on a tester, that diamond must be verified with a series of test blocks. Then, you can use THAT diamond on THAT tester. If you want to add another diamond to the mix, that diamond must also be verified by a series of test blocks on that same tester.

I would think you would end up with a folder for tester SN XXXX, and then a list of serialized diamonds that have been verified for use on it. Each of those diamonds will have it's own certificate, and another certificate showing the test block verification for that machine.

And what this all gets you is the big mystery. You've paid more money for indenters, you've paid more to have your tester verified with these indenters,
and you probably won't see much, if any, changes in your results.

This is a great reason for users to join ASTM and get on these committees.
Then you get a vote on procedure changes like this. :notme: