[NTYNUT (OP)]

Hello
I fond this machine what does it do?
http://www.newmaker.com/product-1000-Hardness-Testing-Instrument-Zwick-ZHU-187,5.html

[Ophiolite]

Hello
I fond this machine what does it do?
http://www.newmaker.com/product-1000-Hardness-Testing-Instrument-Zwick-ZHU-187,5.html

It does exactly what its name suggests it does: tests the hardness of materials.
Specifically it can be used (as the text of your link says) for determining Vickers, Brinnel and Rockwell Hardness - three different measure of materials hardness. Click on the links for more information on each.

[NTYNUT (OP)]

Hello
i seen but how it work why it is used in industry

[Bored chemist]

why it is used in industry

Why do you think industry might use a machine that measures hardness?

[evan_au]

why is (hardness) used in industry?

Hardness is a property of all solid materials.

It is important to know the hardness of the materials you are using:
- Sometimes we want to choose a material that is very hard, so it can cut other materials, or so that it does not change its shape very much when put under pressure, or just so it will last a long time (like jewellery). An example might be the drive shaft joining a turbine to an electricity generator, which must not change shape despite considerable forces.
- Sometimes we want to choose a material that is not very hard, so it can be flexible in the presence of vibration, so that it can be more easily cut or shaped, or so that it acts as a cushion for forces. An example might be the copper wires used in an electricity generator, which must be bent into complex shapes.
- Usually, we want to avoid hard materials rubbing on each other, so we inject a fluid between them to lubricate them, keeping them slightly apart. An example might be the bearings on a turbine or electricity generator.
- More rarely, we intentionally rub hard materials on each other. An example is shaping of diamonds by rubbing them on other diamonds, or polishing them with diamond dust.
See: https://en.wikipedia.org/wiki/Hardness

how does (a hardness tester) work?

See: https://en.wikipedia.org/wiki/Hardness#Measuring_hardness