Let's give you some popular science: what is food-grade stainless steel? What kinds are there?
When buying stainless steel tableware, you often see the words "304 stainless steel". Some merchants say "304 stainless steel is food-grade stainless steel", while others say "316 stainless steel is better than 304 stainless steel", so what are these messy numbers? What does it have to do with "food grade"?
Stainless steel numbers used for tableware and kitchenware include 304, 316, 420, etc., because tableware does not require strong resistance to stress and corrosion, and the use temperature is not very high. For stainless steel, this is a very low temperature. , so the materials used are actually very cheap and commonly used. Many people still don't understand food-grade stainless steel. There are several types of food-grade stainless steel and what is the difference between it and 304 stainless steel.
Is 304 stainless steel the same as food grade 304 stainless steel?
304 is a stainless steel brand, American name. Its Chinese brand name is 06Cr19Ni10, which is very complicated and difficult to read, so we are more accustomed to calling it "304 stainless steel".
Is 304 stainless steel the same as food grade 304 stainless steel? no the same! Food grade and brand belong to two systems, but they are inextricably linked. Just like a person can be both a man and a father - does a man have to be a father? uncertain.
The same is true in the field of stainless steel. The grade determines the corrosion resistance of stainless steel. As for whether it is food grade, in addition to the corrosion resistance of stainless steel, there are also requirements for the precipitation indicators of five heavy metals: lead, chromium, nickel, cadmium, and arsenic.
Later, it was discovered that stainless steel that can meet the heavy metal precipitation requirements can also meet the grade requirements. Therefore, in the national standard GB9684-2011 "National Food Safety Standard Stainless Steel Products", the grade requirement was canceled and only the precipitates of heavy metals were required (it was just a different way of saying it, which is actually similar to the requirements of the old national standard), so today's There is no requirement for the grade of stainless steel used in tableware, but at the same time, as long as it can reach food grade, it must reach at least the level of 304 stainless steel.
Looking back now, food-grade 304 stainless steel is 304 stainless steel that meets heavy metal precipitation standards; while ordinary 304 stainless steel has not been tested according to the national standard GB 9684.
The name of the old national standard GB 9684 is "National Food Safety Standard Stainless Steel Products". This national standard has been replaced by GB 4806.9-2016 "National Food Safety Standard Metal Materials and Products for Food Contact" in 2017 (this new national standard merges the original Applicable to two national standards of stainless steel (GB 9684) and aluminum (GB 11333)).
In other words, food-grade stainless steel refers to stainless steel that complies with the national mandatory standard GB4806.9-2016 "National Food Safety Standard Metal Materials and Products for Food Contact".
Regarding stainless steel tableware, the new national standard (GB 4806.9) stipulates:
4.1.3 Stainless steel tableware containers should be made of austenitic stainless steel, austenitic ferritic stainless steel, ferritic stainless steel and other stainless steel materials;
Food-grade stainless steel mainly includes 304 stainless steel and 316 stainless steel
1. 304 stainless steel can resist corrosion and oxidation by chemical substances. The standard material of stainless steel pressure cookers is 304 or above.
2. 316 stainless steel is better, contains 10% nickel, is more corrosion-resistant, is widely used in medical applications, has no metal ion precipitation, and is very safe.
The difference between food grade 304 and SUS304 stainless steel
SUS304 refers to 304 stainless steel. SUS is a Japanese material standard, and 304 stainless steel is a grade of stainless steel produced in accordance with American ASTM standards. 304 is equivalent to my country's 06Cr19Ni10 stainless steel. Japan also quoted the name of the United States and called it: SUS304. SUS304 is not necessarily food grade stainless steel, it is just a Japanese brand mark.
