center punch for psi testing

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I use a second-hand Scleroscope for steel and a durometer for soft material.

The Scleroscope reads correctly only on smooth flat surfaces of relatively heavy objects.

-jsw

A Rockwell tester does it with a diamond point while other testers do it with a small ball.

y consistently to show difference between materials resistance to psi press ure. The manufacturer I work with demonstrates this with a center hole pun ch. But I'm looking for something a little larger in impact area and that has some way to set the psi impact. Any ideas?

I do not understand what you mean by psi. But my thoughts on a hardness te ster would be to use a fairly small ball from a ball bearing. The balls ar e consistent in size, quite hard, and cheap. Put the ball on the material being tested and drop a weight through a tube on it. The tube would make s ure the weight hit the ball and would ensure the height of the drop was con sistent. Then measure the diameter of the mark on the material using an op tic scale.

Dan

Do a web search for 'brinell hardness tester' . Here's the wiki page on this: