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In stainless steel grades, what do EP, BA, AP, and MP mean? And where are they used respectively? What do 2B and BA stainless steel sheets mean? AP: Anneal treatment & Passivation / Acid pickling ； MP: Mechanical Polish ； BA: Refers to vacuum bright anneal tubes (Bright Anneal treatment)/Bright Annealing; it is an abbreviation for atmosphere-controlled heat treatment (Bright Annealed). It is also known as stainless steel BA tubes, clean tubes, bright anneal tubes, seamless tubes, gas pipeline tubes, high-purity gas pipelines, and sleeve tubes ； EP: Electropolished tubes: The inner surface of high-quality BA tubes is electropolished; subsequently, they are purified with ultrapure water and packaged under nitrogen atmosphere. Pipeline material processing procedures, for reference: EP: Bright annealing --> Non-destructive testing --> Chemical polishing --> Electrolytic polishing; BA: Bright annealing --> Non-destructive testing --> Single cleaning; CP/AP: Heat treatment --> Non-destructive testing --> Chemical polishing. What do 2B and BA stainless steel sheets mean? Processing steps: Cold rolling --> Annealing and pickling --> Leveling for 2B sheets; Cold rolling --> Bright annealing --> Leveling for BA sheets. After cold rolling, it undergoes heat treatment and pickling, followed by finish rolling to achieve a moderately bright surface. Thanks to its smooth surface, it can be easily re-ground to make the surface even shinier. It has a wide range of applications, such as in tableware and building materials. After applying surface treatment to improve mechanical properties, it meets almost all applications. The main difference between BA and 2B lies in the annealing process: 2B undergoes annealing and pickling, resulting in a certain degree of oxidation on its surface, which gives it a darker appearance ； BA bright annealing: the surface does not oxidize and remains bright. A product obtained by bright annealing BA after cold rolling, followed by leveling. It has an excellent surface gloss and a high reflectivity. Like a mirror-like surface. Used in home appliances, mirrors, kitchen equipment, decorative materials, etc. All stainless steel sheets are classified into 2B (i.e., cold-rolled) and NO.1 (i.e., hot-rolled), with the difference lying in the sheet thickness and surface finish. The thickness of 2B sheets is ≤3.0, while that of NO.1 sheets is ≥3.0. The same applies to 304J1 sheets, which can be divided into 304J1/2B and 304J1/NO.1. 2B sheets have a smoother surface than NO.1 sheets, allowing for processes such as drawing or polishing, whereas NO.1 sheets cannot undergo such treatments. Of course, 2B sheets are more expensive than NO.1 sheets. For the same material, whether it is a 2B finish sheet or a NO.1 finish sheet, its chemical composition is identical.