What material is used for hinge pins?

The correct answer involves the use of SUS304, which is a specific grade of stainless steel known for its excellent corrosion resistance and durability. This material is particularly suited for hinge pins in dry van applications because it can withstand various environmental conditions, including humidity and exposure to different substances that may cause rust or degradation in other materials.

SUS304 stainless steel also exhibits good strength and toughness, making it reliable for structural components like hinge pins that are subjected to wear and mechanical stress during operation. This is crucial, as hinge pins must ensure the consistent and smooth operation of the doors without failure.

In contrast, other materials like aluminum and copper, while having their own benefits, may not offer the same level of strength or resistance to wear as SUS304. Aluminum could be prone to bending or breaking under significant stress, and copper, while resistant to corrosion, does not generally provide the same mechanical strength needed for hinges in heavy-duty applications.