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TRX
05-19-2012, 03:48 PM
Several places are selling this portable hardness tester:

http://www1.mscdirect.com/cgi/NNSRIT2?PMAKA=00933861&PMPXNO=4759213&cm_re=ItemDetail-_-ResultListing-_-SearchResults

Nobody says who the manufacturer is, just "Made in USA". And I can't find a manual online for it, either.

Does anyone have any experience with these or similar portable testers? The price, compared to a "real" tester, looks too good to be true.

loose nut
05-19-2012, 04:22 PM
It's a good bet that the manufacturers name actually is "Made in USA" but is made in China.

Duffy
05-19-2012, 04:30 PM
It all depends on what the measurement is to be used for. For water of a quality that most people would cheerfully drink, there is a linear relationship between hardness and conductivity. After all, "hardness" is only a measure of the water's ability to consume soap-nothing more scientific than that.
Now if you want some SCIENTIFIC measurements, then get a meter and a bunch of specific-ion electrodes and measure for calcium, magnesium, carbonate, and sulphate. Oh, and dont forget iron! This will cost ya.

John Stevenson
05-19-2012, 04:35 PM
I could do with one of those when I go shopping at the supermarket.
Is it just me or does anyone else watch whilst someone goes up, squeezes the bread and then walks on.

The result is the loaf I pick is is work hardened to 64 Rockwell :confused:

Toolguy
05-19-2012, 04:48 PM
It all depends on what the measurement is to be used for. For water of a quality that most people would cheerfully drink, there is a linear relationship between hardness and conductivity. After all, "hardness" is only a measure of the water's ability to consume soap-nothing more scientific than that.
Now if you want some SCIENTIFIC measurements, then get a meter and a bunch of specific-ion electrodes and measure for calcium, magnesium, carbonate, and sulphate. Oh, and dont forget iron! This will cost ya.

I don't think ROCKwell hardness means the minerals in water.:rolleyes:

customcutter
05-19-2012, 04:49 PM
The only 2 hardness testers I've seen or used left a small mark like a center punch. Don't know how you can tell the hardness without maring the surface?

Ken

Bob Fisher
05-19-2012, 05:09 PM
The device is called a schlerometer, Hardness being measured by the height of the rebound. Maybe good to say +- 5 points when used properly.Bob.

MichaelP
05-19-2012, 05:15 PM
Don't know how you can tell the hardness without maring the surface?
By using a bouncing ball method, for example. The harder the base, the higher the ball will bounce (I strongly suspect that's what the device in the OP does). Scleroscopes work on this principal using a falling hummer with a diamond point. There is also a more modern implementation of this method in so called Leeb rebound hardness testers.

There are also ultrasound non-destructive methods in existence.

customcutter
05-19-2012, 05:28 PM
The device is called a schlerometer, Hardness being measured by the height of the rebound. Maybe good to say +- 5 points when used properly.Bob.

When I was making custom knives, I would have been highly ticked if I ordered Rc 59-60 on my blades from the heat treater and they came back 54-55.

I could have told closer what the Rc was by dropping them on the concrete and listening for the correct tone.

Maybe it should be called a hardness estimator?

thanks,
Ken

TRX
05-19-2012, 05:37 PM
Maybe good to say +- 5 points when used properly.Bob.

That's why I was looking for a manual. Argh. I don't expect extreme precision, but "somewhere between 45 and 55 Rc" doesn't seem particularly useful for my purposes.

MichaelP
05-19-2012, 05:46 PM
If you're OK with a small dent, look into Ames portable hardness testers on eBay. You can buy one quite inexpensively. They're sufficiently precise.

gwilson
05-19-2012, 08:12 PM
Those type testers require a fairly THICK test piece to give any accuracy. I do not advise getting one unless you are making large,thick items. The ball won't bounce accurately on smaller objects.

oldtiffie
05-19-2012, 08:32 PM
If I were looking for a good hardness tester (which I'm not as I don't need one at present) I'd seriously look into this one:

Machine:
https://www.machineryhouse.com.au/Q520

Manual:
http://images.machineryhouse.com.au/Q520/PDF/Instruction%20Sheet

It is made by "Measuremax" (probably Chinese) but I have several Measuremax electronic tools and they are excellent.

TGTool
05-19-2012, 10:19 PM
When I was making custom knives, I would have been highly ticked if I ordered Rc 59-60 on my blades from the heat treater and they came back 54-55.

I could have told closer what the Rc was by dropping them on the concrete and listening for the correct tone.

Maybe it should be called a hardness estimator?

thanks,
Ken

All the heat treaters I know use a better hardness tester. They come with a standard to verify calibration and the readings are pretty consistent. And perhaps this other method could be called an estimate.

Duffy
05-19-2012, 10:47 PM
MY Bad! Appologies for the attack of stoopids.:o

MichaelP
05-20-2012, 05:45 AM
It is made by "Measuremax" (probably Chinese) but I have several Measuremax electronic tools and they are excellent.
Looks like the correct spelling of the brand is MeasumaX

gwilson
05-20-2012, 08:44 AM
You guys need to forget about the portable testers. They don't work on little things like knife blades.

MichaelP
05-20-2012, 08:49 AM
Ames portable testers will work on knife blades just fine. But they're regular destructive testers that leave a small indentation.

bborr01
05-20-2012, 09:33 AM
When I was working we had a machine that checked the hardness of ball bearings by bouncing them off from a hard plate. It was called the "BALL BOUNCER". That got a few laughs.

It didn't exactly check specific hardness, but bounced the balls that were hard and the soft ones just rolled off the hard plate. That may be similar to how this one works.

Brian

customcutter
05-20-2012, 11:04 AM
All the heat treaters I know use a better hardness tester. They come with a standard to verify calibration and the readings are pretty consistent. And perhaps this other method could be called an estimate.

Yes, the commercial heat treater I used in Tampa had one similar to the one listed on the same page, I think it was about $2500 if I remember. I know some of the guys who used to forge their blades would use different files to check hardness. They are also listed in that catalogue.

Ken

javman
05-20-2012, 10:00 PM
We use an Equotip 2 made by Proceq to test the hardness of mill work rolls for the steel industry. We check for work hardening of the rolls after grinding them. It does leave a very small mark on the surface.

http://equotipassoc.com/

I see they now have a newer model. Equotip 3. I have used the same unit for almost ten years and the only problem is the cable has been replaced maybe twice. Costly but they are very good units.

flylo
05-20-2012, 11:39 PM
Just bought this Detroit brand bouncing ball type on ebay today. Item number: 160801133818 Looks to be in good shape with case & directions.
Here's the company link http://www.detroitflame.com/HardnessTester.htm
They only sell for $105.

BobL
05-21-2012, 12:07 AM
I could do with one of those when I go shopping at the supermarket.

I do the reverse.

One of my "hobbies" is making wood work tools. While I do purchase stock tool steel and shape, harden and temper it accordingly, sometimes I find the thickness I need in the form of a cheap tool in a big box hardware store. I have been know to buy cheap tools and take them back to the lab and measure the hardness and then take the ones I don't want (often all of them) back. They all have a few dimples in them that no one would ever notice unless it was pointed out to them.