Because stainless steel won't rust because its main component is nickel, which is expensive and not very hard. Only suitable for some decorative items that do not need to be used vigorously. Such as railings, tableware and so on. Bridges, ships, etc. , are hard to eat, so soft things are solid, and expensive, who can afford it! That's too extravagant. Stainless steel is divided into 201304316316l, which is determined by the nickel content. Generally, decorative tubes are 20 1 with little nickel content. Nickel is a rare element, and its price is controlled by the London Futures Exchange. You can check the price of stainless steel on the website at a glance.