1. Magnetic Test: Stainless steel is generally not magnetic. In other words, it does not stick to a magnet when brought into contact with a steel surface. If a material is magnetic, it is likely not stainless steel.

2. Color and Shine: Stainless steel surfaces are typically bright and silver in color. Stainless steel is resistant to staining and oxidation, so it does not develop stains or rust over time.

3. Carbon Test: Stainless steel has a low carbon content. Therefore, it may be possible to determine the material's content by performing a carbon test.

4. Rust Test: Stainless steel is a material that does not rust. You can check if it rusts by applying an acid (e.g., a saltwater solution) to the stainless steel surface. Stainless steel does not form rust.

5. Material Hardness: Stainless steel is generally a hard material. You can use an appropriate hardness measurement device to test the material's hardness.

6. Identification Labels: Stainless steel products often carry identification tags or markings that specify the type and quality of the material. These labels can be used to confirm that a product is made of stainless steel.

7. Experienced Observation: An experienced observer can visually distinguish stainless steel from other materials. Stainless steel surfaces often have a distinct shine and texture that are characteristic features. 

For a definitive diagnosis regarding stainless steel, you may need to consult an expert laboratory to determine the material's properties. However, the methods mentioned above can be useful for basic testing if you suspect that a material is stainless steel.