Stainless steel is an alloy based on iron mixed with chromium and nickel. Chromium and other substances form a strong oxide film on the surface, making it a metal that is resistant to corrosion. It is a "rust-resistant" metal. The alloy component chromium forms the passivation film. This film has the property of repairing immediately, even if it is destroyed by scratches, etc., but corrosion occurs in an environment where the film is deteriorated and destroyed. It does not look like red rust on iron, but it causes various corrosion depending on the conditions and environment.
The resistance to corrosion is called "corrosion resistance." The most important purpose of using stainless steel is this corrosion resistance.
Various stainless steel types are made depending on the type and ratio of the added metal. Stainless Steel 304 Bolts is a general term for these steel types. Iron is the base alloy, so make no mistake.
The material code for stainless steel is SUS. A three-digit number is added after SUS to distinguish the Stainless Steel 316 Bolts type. Many of the others are special steel types that are made according to the application (for large consumers) and can be considered special. Grade 8.8 Bolts other type of stainless steel. It is often abbreviated as "stainless steel," but in the English sense, it means rust and dirt. But it's well-established as a popular name, so that's fine.
There are roughly two types of stainless steel that the general public can distinguish, one that attaches to a magnet and the other that does not. Stainless steel threaded rod manufacturers provide you the best quality stainless steel.
The main additive elements of non-magnetic steel grades are chromium (Cr) and nickel (Ni). In the symbol, numbers in the 300s are attached with name of Stainless steel metal. It is called austenitic stainless steel. The inclusion of nickel improves corrosion resistance and heat resistance property. The price is (obviously) more expensive than the above ferritic stainless steel. It is also called nickel stainless steel. Parts, where the material has deteriorated due to rigorous processing or welding are slightly magnetic and easily corroded.
The nickel-based stainless steel plate (2B surface, described later) has a silver-white colour due to the nickel component. If you compare them side by side, even the general public can see the difference. However, when it comes to processed products, surface treatment and polishing are applied, and stains are attached, making it difficult to distinguish by colour.
In addition, based on the above two steel grades, stainless steel (steel grade) with various characteristics is made by adding a small amount of several kinds of elements. The more metal components added, the higher the price. In particular, rare metals such as Mo and Ti are very expensive, so their added steel grades are very expensive materials.
In addition, there are low carbon materials with a very small amount of carbon (carbon / C) in major steel grades. Carbon is an element that affects the strength (hardness) of a material and causes corrosion and cracking.