Home Made Hardness Tester?

[JFriis]

It cant be that hard, can it?

Make a tool, determine what pure lead tests at and then go from there?

Is it possible to make accurately?

[Kraschenbirn]

Yep, it can be done but, IMHO, it's kind of like reinventing the wheel with the reasonably accurate (and relatively inexpensive) Lee Hardness Tester Kit so readily available. The simplest "do-it-yourself" technique would be based upon comparison against a known standard (i.e. as you suggested, a pure lead sample) and, at the very least, require purchase of a decent optical comparator. If you have (or can obtain) access to a copy of E.H. Harrison's "Cast Bullets", it contains a reprint of Harrison's Jan. 1959 American Rifleman article "Measuring the Hardness of Cast Bullets" that describes the methodology and math.

Bill

[Pepe Ray]

In case you don't have Krashinburn's reference book'
Ingots are simple. They should be uniform and handy in size, with a smooth flat surface.
You need a vise of proper size. A proper size micrometer caliper and a reclaimed ball bearing of 1/2" TO 3/4" IN diameter. A sample ingot of known content to press in the vise with the unknown, squeezing the ball between. Measure the resulting indents and use the formula to calculate the needed result.
(I'd have to go look up the formula)
Estimating already cast boolets requires commensurately more sophisticated and smaller tools. I usually just take a known and an unknown and base to base them in the vise. The fatter being the softer. If you NEED more specific numbers you should spring for a tool. Either Cabin Tree or LBT.
Pepe Ray

[JFriis]

Thanks for the help. I will deffinately look into the book and just spring for a hardness tester somewhere along the line.

[montana_charlie]

If you drop a large ball bearing through a length of 3/4-inch pipe, it will make a dent in pure lead.
Measure the diameter of that dent.

If you always use the same piece of pipe, and the same ball bearing, you should be exerting the same impact on anything you try it on.

The diameter of the dent will change as you use it on different alloys.

CM

[runfiverun]

a staple gun can give you an idea of alloy[bhn any ways] with some practice and some knowns.

[fourarmed]

As the previous posters suggested, you need to indent the test ingot with a ball bearing, and a pure lead ingot WITH THE SAME FORCE. The way I do it is to lay one ingot on the bench top, put the ball bearing on it, hold the other ingot on top of the ball, and whack the top one with a hammer. If the reference ingot is pure lead, the indent will be larger than in the test ingot. Divide the diameter of the larger indent by the smaller, square the result, and multiply by 5, which is the Brinnell hardness of pure lead. Do it several times to improve the precision of the result. Accuracy depends on how pure your reference ingot is.