Household stainless steel cutlery can be divided into three levels of 430, 18-8, and 18-10. 430 stainless steel, which is composed of iron +12% or more, can prevent oxidation caused by natural factors. It is called stainless steel, but it will rust after prolonged use. 18-8, its composition is iron +18% chromium +8% nickel, 18-10 its composition is iron +18% chromium +10% nickel. Chromium is a material that does not rust the product, and nickel is a corrosion-resistant material. The higher the nickel content, the better the quality of the product and the more expensive it is. Strictly speaking, products containing only chromium and not containing nickel are stainless steel, and products containing both iron and nickel are stainless steel. It is important to select the stainless steel product to see the code. If there is no print code on the product, it is generally a nickel-free product. Since nickel is a diamagnetic material, it is usually possible to try it with a magnet when it is purchased. Stainless steel products are attracted to the magnet and stainless steel products are not attracted to the magnet. There have been two types of stainless steel products marked "201" on the market, the composition of which does not meet the relevant standards of stainless steel, but the brand of stainless steel appears on the market. On the surface, this product is difficult to distinguish from ordinary stainless steel, and it is non-magnetic, which is very easy to cause confusion among consumers. It is the "Li Gui" in stainless steel. The simplest way to judge it is that it is cheap. Real high-quality stainless steel must be a price-for-money, expensive reason. Chemical method can be used to identify the authenticity of stainless steel. In 100mL distilled water, 8g of anhydrous copper sulfate is added, and then 3 drops of concentrated sulfuric acid are added. The solution is dropped on the surface of the stainless steel product for 6 minutes, and the surface of the real stainless steel product does not change. A layer of red material is produced on the surface of the unqualified product.

In addition to the purchase of stainless steel products should also pay attention to the following two aspects: a look at the color, the color is black and black, it is likely to be stainless iron; the color is dark and red, it is likely to replace nickel with manganese. 2 touched by hand, the edge can not have burrs, the surface is smooth, no scratches, no blisters.