Crude hardness testing (shade tree method ?)

[Digger]

Don't have a official commercial test set up but thought I would try something out.
I took a 5 ft length of 1" pvc pipe and held it straight up resting on one of my ingots of coww's .....used a bearing ball of 7/8" size and dropped it into the pipe , striking the ingot.
Did this three different times and got a eyeball with magnifying glass and calipers size of dent .120 average ....
Did the same set up and number of drops with a ingot of range lead and got an average of .115 ..

Call me crazy but would this make (since I have no reference scale) my range lead quite a bit harder ?
All this is just a guess as I don't know how the Lee exactly works or the Cabin tree or others but if this is true it does give me a direction to go with .
I have a pencil set some place but thought I would play with this for a bit today ....
digger

[rmatchell]

Sounds like a good idea to me.

[Digger]

Can't tell it's too cold to do any thing else today ...:roll:.... did the pencil test with the coww ingot and scratched it w/2b and not with 3b .....

[Jim Flinchbaugh]

While your described method wont give you hardness numbers, it certainly will give you comparison numbers.
You can also put the steel ball between 2 different samples of lead and squeeze them in a vise.
The bigger dent is obviously the softer stuff. No numbers,
but it's a way to sort out "this one is harder than that one"
BTW, becasue of spring back the "drop test" may not be the best.
Squeezing a ball bearing between 2 samples in a vice, held under pressure for 30
seconds as the Lee tester suggests, will give more consistent results.
The ball drop tests works well for a hardness test IF you have a way to measure
how high it bounces after hitting the sample

[Digger]

Thanks lots for the info Jim , always learning ....(that's what's fun )
digger

[Jim Flinchbaugh]

the learning is the fun for me as well.
BTW, I'm just regurgitating what has been taught to me.
There actually is a hardness tester that uses a steel ball inside a vial with a scale on the side
(the ones I have seen)
If you're so inclined, google "scleroscope" and "Leeb rebound hardness testing"

[Starvnhuntr]

Although I have no idea about hardness numbers I have a crude method of putting te same type of bullets base to base and squeezing them in the vise. after a few years of doing this and a bunch of tubs of labled bullets I think I can get a pretty good idea how hard my bullets are. in comparison anyway.

[runfiverun]

you have something simple and repeatable it's good nuff for harder than this,softer than this, piles of ingots.
i have used a staple gun,and the thud test before, to sort mostly known and some unknown mixed ingots before.

[HamGunner]

I use a similar method to your bearing drop to give me an approximate hardness reading of my different alloys. It is not really as accurate as to actual true BHN I suppose, but it is fairly accurate as to just were the alloys fit along a scale of hardness between dead soft lead and some other known harder alloy. I JB welded a ball bearing to a steel rod (or cut off bolt) that I ground convex on one end and then I wrapped a long length of lead solder around the bolt for weight and wrapped that with electrical tape till it was a slightly loose fit inside of a piece of pipe. My pipe was 5ft long, but the length of the drop does not matter as long as it remains the same with each drop.

Get a piece of dead soft lead as pure as you can find it and drop the weighted bearing onto an ingot of that lead for a base to use in your later calculations. Drop it several times to get the average diameter of the indentation. I use a magnifying glass to read the diameter using my micrometer. PB is the average diameter of the soft lead indentation. Use the following formula to get a decent reading of hardness and I call it BHN although it is only a representation of approximate BHN as this is not to be expected to be exact. But it is a very good indication of just where along the scale of known hardness your unknown alloy will fit with your soft PB given a reading of 5 BHN on your scale.

[(PB)2 divided by (?)2 times 5 = BHN] That is PB or soft lead squared divided by the average of the measured unknown alloy squared times 5 to equal the approx. BHN of that unknown alloy ingot. A flat piece of alloy that is probably at least 1/4 inch thick would probably give an accurate enough reading, but the tested ingots need to always be about the same size to make sure that the readings can be compared to other readings. I always just use a one pound ingot that I have poured into my Lyman ingot mold that has had sufficent time to age to it's eventual hardness. I usually wait at least a couple of weeks before testing and then I might even retest later on to see if the alloy has hardened further. When I am convinced of it's approximate hardness, I use metal numbered stamps to mark all the ingots in that batch as to it's hardness or by lettered stamps such as WW for wheel weight, LT for Linotype, or PB for soft lead, etc. with notations in my notes as to just what that designation measures in approx. BHN.

This may sound complicated, but it is actually very simple and repeatable. I do not care if my alloy is really say, 14.5 true BHN instead of my measured 13 or 15 as that is close enough for what we are doing. My old WW metal comes out to about 11 BHN and my Linotype that I melted down from type measure close to 17 BHN and it had undoubtedly lost a bit of it's tin and antimony and thus is a bit softer than the normal 21 BHN of fresh Linotype. I have some 29 lb. pigs of Linotype metal that the print shop had remolded into pigs, that I got at the same time that I bought their small type pieces and it measures a bit harder at about 19 BHN. I use this straight (depleted Linotype metal) for my faster rifle bullets and they work great and they do not fragment like pure Linotype does, so I think my measurements are fairly close. Close enough for me and that is who I am trying to please. :drinks:

[nanuk]

( Known diameter ) ( Known diameter )
-------------------------------------------------- X (BHN of Known alloy) = BHN
( Unknown diameter ) ( Unknown diameter)



this formula can be used for any "Unknown" alloy IF you have a "Known" alloy, and will work with any "Known" alloy.

and by "Known" I mean you know the BHN of said alloy.

this formula is available from reputable sources in numerous incantations, but they all pretty much work the same way.

Use two beer bottle caps, fill one with Known, one with Unknown.
When cool, take a hardened ball bearing, the bigger the better... try for at least 1/2" diameter or more.
place the bearing between alloy samples and squeeze in a vice to get a indentation at least 1/2 the diameter of the bearing.
Measure as accurately as you can.

[Digger]

Excellent input here fella's ... thought I might be just a little on the crazy side playing around like that but didn't know I was in the "ballpark" ....
Thank you for the detailed discussion of the different techniques involved ...