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    Default Looking for soft hardness testing files ....

    ...or other inexpensive objects of calibrated hardness with which I can test my objects of undetermined hardness. I have a set of the ubiquitous set of six in the range of RC 40-65, but I need testing in a range lower than that. Do softer test files exist, or some other similar item?

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    The problem with a soft hardness testing file is that it would quickly wear -- and even new would have even less +/- accuracy than the higher Rockwell ones you're familiar with.

    There are some fairly cheap rebound testers that work OK for flat and fairly thick surfaces.

    What are you trying to measure? Could be something like a used Ames hardness tester would be the ticket - just make sure the indenter(s) are good.

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    If you have a microscope and can get a Vickers indenter, it's easy to apply the necessary force and calculate the hardness. If you have an Accufinish tool grinder or some other precise way to lap, you can even put the Vickers geometry on the broken end of a 1/8" carbide whatever. Carbide will work fine on everything up to fairly hard metals. Lot's of fundamental info online.

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    Quote Originally Posted by PeteM View Post
    The problem with a soft hardness testing file is that it would quickly wear -- and even new would have even less +/- accuracy than the higher Rockwell ones you're familiar with.

    There are some fairly cheap rebound testers that work OK for flat and fairly thick surfaces.

    What are you trying to measure? Could be something like a used Ames hardness tester would be the ticket - just make sure the indenter(s) are good.
    Target pieces are thin (usually 1/16" thick) 0-1 and 4130 die plates.
    Sounds like that's too thin for the Ames ?

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    duplicate post
    Attached Thumbnails Attached Thumbnails b-hand.jpg  

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    I do not have those things. I think some home made scratch sticks will do the job. I work in a closed system : nobody is measuring my tools and I don't state anything very specific about their hardness, and so, pieces hardened and tempered like I do my tools would work to gauge hardness of said tools, because they are all (scratch sticks and tools) hard relative to each other, for my purposes re: testing.

    The 45-60 test files give me a reference to the outside , real world, which is great, but the data I need now will be of the self-reflecting sort (scratchers and tools), and not necessarily the objective sort. Tool example : RT/Pancake blanking die b-hand.jpg These can't be tempered very hard or they snap, or crack from long term fatigue. This one is either 1/16" or 3/64" thick 0-1 flat stock.

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    We had a heat treat vendor take a box of files and temper then back to a 50 HRC hardness that we used until a Vickers hardness tester could be bought to use. But to temper back to less than 40 HRC. That may and may not work. Not sure a scratch test from a 20 HRC file would be any different than that of a 35 HRC file. Be too hard to tell. You would have to calibrate your lightly applied force to control the amount of force needed to make the cut without damaging the teeth on the file. .

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    Quote Originally Posted by 4GSR View Post
    We had a heat treat vendor take a box of files and temper then back to a 50 HRC hardness that we used until a Vickers hardness tester could be bought to use. But to temper back to less than 40 HRC. That may and may not work. Not sure a scratch test from a 20 HRC file would be any different than that of a 35 HRC file. Be too hard to tell. You would have to calibrate your lightly applied force to control the amount of force needed to make the cut without damaging the teeth on the file. .
    That is really interesting, and a little discouraging, but I think I'll be able to do enough cross-reference scratching between my exising dies (not all the same hardness, by design) and the soon-to-be set of scratch sticks. I think.... and hope.

    I like the idea of calibrated force; that sounds worth devising something simple for, if the scratch stick plan doesn't work.

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    Make friends with a house that has the equipment.
    A lunch at Burger King is all it it takes in most cases. There is the titty bar and and that can buy a whole lot of free part testing.
    Bob

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