The main performance of an SS304/304L 6mm THK hot-rolled stainless steel sheet plate with ASTM A240/A240M specification and a hairline finish includes:

1. Corrosion resistance: SS304/304L stainless steel is known for its excellent corrosion resistance, especially in non-marine environments. The hairline finish does not significantly affect the corrosion resistance properties of the stainless steel.

2. Surface finish: The hairline finish is a brushed finish that creates a fine, directional grain pattern on the surface of the stainless steel sheet plate. It provides a distinctive and visually appealing aesthetic to the material.

3. Strength and durability: SS304/304L stainless steel has good strength and durability, even with the 6mm thickness. It can withstand wear, impact, and deformation, making it suitable for applications that require structural integrity and resistance to damage.

4. Formability: Hot-rolled stainless steel sheets, including those with a hairline finish, have good formability. They can be easily bent, shaped, and formed into various configurations without compromising their structural integrity.

5. Heat resistance: SS304/304L stainless steel has good heat resistance and can withstand high temperatures without losing its strength or corrosion resistance properties. This makes it suitable for applications that involve exposure to elevated temperatures.

6. Easy maintenance: The hairline finish of a hot-rolled stainless steel sheet is relatively easy to clean and maintain. It resists staining, fingerprints, and smudges to some extent, but may require regular cleaning for optimal appearance.

Overall, an SS304/304L 6mm THK hot-rolled stainless steel sheet plate with an ASTM A240/A240M specification and a hairline finish offers good corrosion resistance, strength, durability, formability, heat resistance, and an aesthetically pleasing appearance. It is suitable for a wide range of applications in various industries, including architectural, interior design, and decorative applications.