Lead hardness tester DIY concept... maybe ?

[bgoff_ak]

So it sounds to simple to me, so someone help identify the fault. #1 be aware I don’t have a hardness tester. That being said if the measurement is area of pressure over time what would be wrong with getting a say 5 pound weight and letting it fall onto a slug of I don’t know lets say .225 X .750 and then measuring the height of the slug. It’s the same principal just over a much shorter time. It would be my assumption that this could be as simple as a weight at a fixed distance through PVC etc to keep it square ( on impact ) there also the hammers on a fixed axis that would accomplish the same task. I would assume you would be getting a better test as the media would always be the same diameter more of a standardized test, then testing this and that in differing configurations like with other commercial testers. It seems to me the configuration of the substrate would generate differing reading by the nature of the flow properties from the pressure. So I’m thinking of this more as a scatter plot / weighted average I don’t really need to know that its 6.8 vs 6.6 BHN, more of pure lead deforms to .500”/.750” of an inch and uncut WW are .625”/.750” and zinc is .725”/.750” I searched for this idea throughout the forums and I didn’t see anything, but if anyone knows if this is a previously shot down blast from the past please let me know. Was kind of curious about if anyone is doing any tensile testing also. So please every let me know your thoughts be it my god man you are genius ! or shoot down my idea like the one about putting little umbrellas, or little red swords with cherries in drinks. I’m going to look into it if it’s never been done I’m going to be a millionaire…

[220swiftfn]

Erm, ok....... Ifn it makes you happy, go for it. But don't expect people to PAY you for it...... There are MANY "home brew" hardness testers out there, one of my favorites was done up by "Jbunny" and used a (slightly modified) spring loaded punch from Harb0r Freight. If I'm reading your post right, you're thinking along the lines of a copper crusher test, which should work out alright. However, the ductility of the alloy wouldn't be tested, just the hardness.


Dan

[bgoff_ak]

Actually the millions was for the drink umbrellas... Not the hardness tester... The second item was for the ductility ie using another measured slug to draw down against and see what it was. Just did not know if any one was testing for this in hollow points etc, maybe I should have made two posts.

[longbow]

Brinnell testing requires a time factor so the material can flow. I suspect (do not know) that softer denser materials may not respond the same to impact as harder less dense materials ~ let's say high strength aluminum compared to lead. Due to density the lead may not "move" fast enough so may indicate it is harder.

However, since all testing in this case would be on lead would it matter? Not sure.

Brinnell tests measures the diameter of the indentation while Rockwell measures depth.

My suspicion is that an impact would work but you would need to have known samples of lead of varying hardnesses to determine the results your tester provided, then make up a chart based on diameter or depth, and it would have to be accurate and repeatable within the limits required for lead boolit shooting purposes.

I have thought much along the same lines but am too lazy to do all that work.

You may be on to something though so have at 'er and let us know how it goes.

Longbow

[bgoff_ak]

my plan tomorrow is to find some thing heavy and drop it... i have some pure and some ww i'll give a whirl. i'll record the results and let you know.

[W.R.Buchanan]

Longbow hit the nail on the head.

The only way you can calibrate your system is to use materials with an exact known hardness, and this must be done with every point of the hardness scale as it is not linier, it is logrithmic.

By the time you have done this well enough to even be in the +/-10 BHN of actual, you will have spent enough time that you could have panned enough gold and bought a real tester that will deliver repeatable results. (Lee, LBT, Cabine Tree, several others)

When you are talking <$50 for a good one, it becomes more obvious why sometimes it is better to not reinvent the wheel.

This is an area in the market place, not needing another choice. Too many good ones out there that have been around for literally 50 years or more.

The Magic 8 Ball says: "Try again later."

Randy