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  1. #1
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    5,559

    Default Information on making a lead hardness tester.

    I am a black powder muzzle loader shooter.
    As such, I am constantly seeking pure lead to cast round balls.
    It can be hard to tell at times with alloys about the place, the marking of pure lead with a thumbnail,not withstanding.
    Therefore I seek a hardness tester.

    Too hard to import a manufactured one at the moment, so I am hoping to make one.
    If you have heard of a homemade one and can direct me to an internet article, I would be obliged.

    I already have one from the Cast Boolits Forum using the drill press and bathroom scales but this type is not suitable when you are at the scrap dealers.

    Thanks

    Grahame

  2. #2
    Join Date
    Sep 2005
    Location
    Bendigo
    Age
    56
    Posts
    146

    Default

    Well here is the instructions for a commercial unit.
    https://leeprecision.com/files/instruct/LT2140.pdf

    From the instructions it gives you a reasonable reference for tip size and angle from there it should be a matter of determining a spring pressure needed for the indenter and having a reference source of pure lead to get the impression size.

    Of course it won’t give you the BHN value unless you have a reference source to compare against but it will compare against a known product.

  3. #3
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    5,559

    Default

    Thank you droog,

  4. #4
    Join Date
    Jan 2016
    Location
    Wodonga Vic
    Age
    35
    Posts
    467

    Default

    Shout out if you need something referenced, I have access to vickers, rockwell and brinell testing gear.

  5. #5
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    5,559

    Default

    Quote Originally Posted by NedsHead View Post
    Shout out if you need something referenced,
    Thanks Mate.

  6. #6
    Join Date
    Jul 2007
    Location
    On the Bellarine
    Posts
    153

    Default

    Grahame,

    I made one some years back for the same reasons as you......I brew my own casting mix and needed to get an alloy mix hard enough for the purpose.

    There are quite a few versions online but I found the simplest using a bore-scope camera attachment or similar microscopic attachment that you can take a still photo from and these come with a grid pattern that is indexed - you need to be able to see that.

    Those endoscope/bore scopes cost about $10 and you can get them from various highly reputable Chinese suppliers You don't need the mega expensive ones for this..cheap and nasty will do as all you need is a photo of a dent.....they usually plug into your smart phone, tablet, laptop etc and run through third party software such as AMCAP....they allow you to screen capture an image. You can spend more dollars and get one that does it all but essentially that borescope and one of those $20 microscope kits they use for looking at circuit boards are all you need

    How they work being you get a ball bearing of a certain size, mount that to a shaft (I brazed mine on) and them use your loading press in reverse to lower a set weight onto that ball which is placed on top of the pill you have cast - use a flat nose as easier to see....I use about 5kgs....It's important you know the exact weight plus the diameter of the ball bearing as it's maths after that....

    You allow a certain time for the 'dent' to be made...important to maintain the same time for all your samples...say 30 seconds....after that time you lift the weight off then use the borescope/microscope to measure the radius of the indentation by using the screen capture mode and the grid template that comes with the bore scope...that tells you the diameter of the dent.

    Use that measurement to check it off against a scale of predetermined hole diameters or you can use the chart online and just put your measurements in...I wrote my own spreadsheet and keep all my measurements to get various ratios of Sn, Pb and Sb. That gives you the approx BHN of your sample tested

    To test how accurate that method is, I sent some samples away and they returned a range of 3% so that's close enough for me.....

    If you need more info then pls drop me a PM and I will try and sort you out......Lee

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