Fasteners Suppliers screws encounter condensate in polluted air. Pollution refers to a large amount of sulfides or carbon oxides. In contact with water, it will form sulfuric acid and hydroxide, which chemically corrode stainless steel screws.
The screw will rust because the protective film of the stainless steel is damaged, the stainless steel is oxidized, and the ability to resist corrosion is weakened, so the stainless steel screw will also rust.
The tensile strength of stainless steel screws with semi-circular heads is relatively uniform in the temperature range of 15~80°C.
As the temperature decreases, the impact toughness of stainless steel screws decreases slowly, and there is no brittle transition temperature. Therefore, stainless steel can maintain sufficient plasticity and toughness at low temperatures.
So what are the precautions for Nanjing screws during storage:
1. The protection of the product should be strengthened during the storage of stainless steel screws. In a dry environment, the electroplated iron screws should not be placed in a damp place.
In addition, care should be taken during the packaging process, not violent packaging.
If non-standard parts with special requirements are needed, they need to be wrapped in a mesh bag or other objects, taking care to avoid colliding with each other.
2. The hardness of the stainless steel screw indicates the ability of the material to resist the pressing of hard objects into its surface.
It is one of the important performance indexes of metal materials.
Generally, the higher the hardness, the better the wear resistance.
Commonly used hardness indexes are Brinell hardness, Rockwell hardness and Vickers hardness.
3. When testing the hardness of stainless steel nuts, there is no heat-treated bolt, only the surface hardness should be within the qualified range.
If it is Stud Manufacturer's heat-treated bolts, it is necessary to have a large hardness on the surface without cutting a diameter. The hardness test is at 1/2R on the surface.