Domestic 38CrMoAIA material, after quenching and tempering nitriding treatment, has a surface hardness of HV860-1000, a nitriding depth of 0.5-0.8mm, and a brittleness of ≤2m grade.

It is made of imported high-strength alloy steel. The vulnerable parts of the screw are plasma surfacing with nickel-based and molybdenum-based alloys 1-1.5 mm thick, which increases the service life by more than 1.5 times.