According to ASTM B265 specification, Any product over 0.187 inch (4.75mm) in thickness and over 10 inch (254mm) in width is classified as plate.

Range of Size: 4.75 - 60.0 tk x <3000 Width x <4000 Length

Other materials like Pure Nickel, Zirconium, Niobium, Tantalum also can be provided.