How to identify whether the material of the cake display cabinet is real 304 stainless steel?

To identify whether a cake display cabinet is made of real 304 stainless steel, a comprehensive judgment needs to be made from multiple dimensions such as material characteristics, detection methods, and certification documents.

The key components of 304 stainless steel (national standard grade 06Cr19Ni10) are 18% chromium (Cr) + 8% nickel (Ni). It has the following characteristics: corrosion resistance: It has strong resistance to acids, alkalis, water vapor, etc., and is suitable for food contact scenarios. At room temperature, it is non-magnetic or only has weak magnetism (processing deformation may produce slight magnetism).

I. On-site rapid identification methods

1. Appearance and tactile inspection

① Check the luster and texture:

Real 304 stainless steel: The surface is evenly shiny without dark spots, scratches or bumps. The edges are smoothly polished without burrs (especially in the area inside the cabinet that contacts food).

Counterfeit material (such as 201 stainless steel): The color is darker or grayish, and the luster is poor. There may be problems such as trachoma and rough solder joints.

② Touch and check the weight:

304 stainless steel has a high density (7.93g/cm³). Under the same volume, it is heavier than 201 stainless steel and has a heavy feel.

When touching the surface, there should be no obvious bumps, especially at the solder joints and seams, which should be smooth without sharp edges (inferior materials may simplify the process to save costs).

2. Magnet test (preliminary screening)

Principle: Due to the high nickel content of 304 stainless steel, it is usually an austenitic structure and is non-magnetic or only weakly magnetic at room temperature (but may produce slight magnetism after stretching, bending and other processing).

Operation: Use a strong magnet (such as neodymium iron boron magnet) to adsorb the surface of the cabinet:

No magnetism/weak magnetism: It may be 304 stainless steel (verification by other methods is required).

Strong magnetism: It is probably not 304 stainless steel. It may be 201 stainless steel (high in manganese and low in nickel with poor corrosion resistance) or ferritic stainless steel.

Note: This method is not absolute (processing may cause magnetism) and needs to be combined with other detections.

3. Stainless steel detection solution (chemical method, the most effective)

Principle: By observing the color change of the metal after reacting with the detection solution, judge whether the content of nickel (Ni) and chromium (Cr) meets the standard.

（1）Operation steps:

Clean the surface to be tested of the cabinet (such as the inner wall, drawer rails and other hidden places).

Drop 1-2 drops of 304 stainless steel detection solution (about 10-20 yuan/bottle for online shopping) and wait for 10-30 seconds.

（2）Observe the color:

304 stainless steel: The liquid is colorless or light yellow (some detection solutions turn red, but the instructions need to be checked).

201 stainless steel: Quickly turns deep red (insufficient nickel content and high manganese content).

Inferior stainless iron: Turns black or dark blue (almost no nickel and easy to rust).

Key points: The detection solution needs to be dropped on the exposed metal surface (avoid coatings and plating layers). It is recommended to test multiple locations (such as corners and welding points).

II. Professional identification methods (requiring tools/data)

1. Spectrometer detection (accurate identification)

Principle: Through spectral analysis of metal element content, directly determine whether the Cr and Ni proportions meet the 304 standard (Cr≥18%, Ni≥8%).

Contact local quality inspection institutions (such as SGS, National Metal Materials Testing Center) and provide samples or on-site testing.

For home use, a portable spectrometer can be purchased (the price is relatively high, about tens of thousands of yuan, suitable for use when purchasing in batches).

Result: Issue a test report clearly indicating the percentage of element composition.

2. Check material certificates and certifications

Manufacturer's qualifications: Regular brands will provide material test reports (such as GB/T 24511-2017 "Cold-rolled stainless steel plate and strip" certification), indicating "304 stainless steel" or the corresponding grade (06Cr19Ni10, SUS304).

Food contact certification: Cake display cabinets need to comply with GB 4806.9-2016 "National Food Safety Standard Metal Materials and Products for Food Contact". The manufacturer can be requested to provide this certification to confirm that the material meets food-grade safety.

Anti-counterfeiting marks: Some brands will stick 304 stainless steel labels in the corners of the cabinet or query material traceability information by scanning codes.

Through the above steps, it can be effectively identified whether the cake display cabinet is made of real 304 stainless steel to ensure food contact safety and equipment durability. Pay special attention to the materials of parts that come into contact with food, such as the inner liner, shelves, and drawers of the cake display cabinet to avoid merchants using inferior materials.