Hardness tester project

[Buckshot]

A question about this...........If you can set a figure for the 'Pure Lead' indent then is it OK to just test the unknown material and use the lead figure as a constant.
If this IS the case, can you place an ingot of 'unknown on either side of the ballbearing and measure both indents or will the calc only work for an ingot on one side?
I know I am 3 years late here but lets just say I am a late developer

.............The indent size in the pure lead sample IS a constant and is the figure used in the formula. The indent in the pure lead is formed under a KNOWN pressure. In order for the formula to work, your unknown alloy also has to be indented with the same pressure. You can make a simple hardness tester with a 4' long piece of pipe, and a steel slug dropped throught the pipe. Place the ball bearing on your pure lead sample, drop the weight and record the imprint OD. Test your unknown alloy similarly, using the pure lead inprint OD as the constant.

.............Buckshot

[DuncaninFrance]

.............The indent size in the pure lead sample IS a constant and is the figure used in the formula. The indent in the pure lead is formed under a KNOWN pressure. In order for the formula to work, your unknown alloy also has to be indented with the same pressure. You can make a simple hardness tester with a 4' long piece of pipe, and a steel slug dropped throught the pipe. Place the ball bearing on your pure lead sample, drop the weight and record the imprint OD. Test your unknown alloy similarly, using the pure lead inprint OD as the constant.

.............Buckshot

That's bloody brilliant - thanks a lot Buckshot

[DuncaninFrance]

GOT THE BITS SORTED AND IT WORKS A TREAT BUCKSHOT - THANKS AGAIN.

[dromia]

Duncan, Buy a tester.

[Wicky]

This is really good guys, I'll knock one up and see how I go, then I'll buy one!