Proof test hammer function: hollowing test. The free expansion of a small metal hammer is designed to test the walls and floor of the hollowing circumstances, through the sound of the beat to determine whether there is hollowing phenomenon wall. Material: aluminum bronze alloy specifications: 0.15,0.25,0.5kg. Proof tools, also known as non-sparking tools, so called non-sparking tools because such work in continuous percussion, friction, impact, impact the process will not collide with each other because of sparks. Currently the material proof tools to beryllium alloys and aluminum bronze alloy material, beryllium copper alloy and aluminum bronze alloy products are not in use because of friction, impact, etc. sparks caused by security incidents. Explosion-proof tool is particularly suitable for use in flammable, explosive, corrosive magnetic and workplace use, for example: these special places military, chemical, petroleum, petrochemical, mining, coal, electronics, gas places in use, proof tools for our Social Security has brought stability but also to our daily production has brought security protection.