It is made of high quality low-carbon-alloy steel. The raw material undergo a rigorous analysis of the chemical composition by forging, through the testing of mechanical properties of hardness, toughness , impact value and intergranular corrosion cracking performance in order to reach the requirement of standards, at the same time owning a good low permeability and mechanical processing performance . Magnetic permeability(mps=1íß105/4íta/m) Average¦u>r1.010 Magnetic field gradient¦í˜bín0.05ª8t It need to be discussed
