What is the difference between the heat treatment codes A and S for SPCC coils?
A: A indicates only annealing; S indicates annealing plus leveling. Currently, because leveling ensures sheet shape, SPCC-A (annealed only) products are rare.
How should I choose between a textured or smooth surface for SPCC coils?
A: If subsequent surface treatments such as spraying are required, a textured surface (D) can improve coating adhesion; if high surface smoothness is required, such as for exposed parts of appliance casings, a smooth surface (B) can be selected.
Why do most domestic steel mills default to the standard heat treatment for SPCC coils?
A: Due to domestic application habits and equipment configurations, annealing + leveling has become a standard process. Uneven products cannot guarantee sheet shape, so unless specifically marked, the default is the standard heat treatment (code S).
The SPCC coil quality certificate only shows tensile strength; how do I select the corresponding hardness grade?
A: You can refer to the correspondence between tensile strength and hardness in the JIS standard appendix. Unless otherwise specified, hardness is expressed as HRB. For thin plates, refer to the conversion relationships of HR30T, HR15T, or HV for selection.
Is SPCC coil suitable for welding?
A: Yes. SPCC is a low-carbon steel. Its low carbon content gives it good weldability. However, surface treatment is required after welding to prevent rusting at the welded area.