Measurement of hardness of metal one of kinds of mechanical tests. The hardness is an integral property, which is determined by many mechanical characteristics of an investigated material.

In the present research influence of effect of Axion radiations (AR) on hardness (microhardness) iron of carbon alloys, in particular, steel and pig-iron was studied, selected from industrial technical is exemplar.

Measurement of hardness conducted on the device PMT-3 at a load 20g, 100g, 200g and increase by microscope 487*. As the pressed tool (indicator) applied a diamond pyramid with the square basis and apex angle between opposite edges 136^O. The outcomes of measurements are listed in table.

As it is visible from a table practically in all cases there was the change of values of hardness at effect AR on a comparison with an initial condition of iron. So, for few - carbon steel of a brand 08J a drop of hardness on 6-8 % was observed. For high - carbon alloys (steel of a brand U-8, pig-iron), on the contrary, increase of hardness on 27.0-35.0% happened, that testifies to happening hardening.

Is thus established, that AR renders influence to atom - crystalline condition of iron - carbon alloys, that is confirmed by change of hardness.