*What is stainless steel and its features?

Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's resistance to corrosion results from the chromium, which forms a passive film that can protect the material and self-heal in the presence of oxygen.

*How is stainless steel classified?

SS are usually divided into martensitic steels, ferritic steels, austenitic steels, austenitic ferritic (duplex) stainless steels and precipitation hardening stainless steels according to the structure state.
The models of stainless steel can be divided into Cr series (400 series), Cr Ni series (300 series), Cr Mn Ni (200 series) and precipitation hardening series (600 series) according to composition.  

 * How are different surfaces of stainless steel formed and its usage?

1) Original surface: NO 1.  Surfaces subject to heat treatment and pickling after hot rolling. It is generally used for cold rolling materials, industrial tanks, chemical industrial devices, etc. 
2) Blunt face: NO 2D.  cold rolling and heat treatment and pickling, the material is soft and the surface is silvery white luster, which is used for deep stamping processing, such as automobile components, water pipes, etc.
3) Fog surface: NO 2B.   cold rolled, heat treated, pickled, and then finish rolled to make the surface moderately bright. it is widely used, such as tableware, building materials, etc
4) Fine sand: NO 4.   It is grinded with 150-180 abrasive belt which is used for bath, decoration materials inside and outside buildings, electrical products, kitchen equipment, food equipment, etc.
5) HAIRLINE: HL.   It is with grinding patterns generated by continuous grinding of polishing abrasive belt with proper grain size (subdivided into 150-320). It is mainly used for building decoration, elevators, doors and panels of buildings.
6) Bright surface:  BA.  It is cold rolled, bright annealed and leveled. Excellent surface gloss and high reflectivity. A mirror like surface, used for home appliances, kitchen equipment, decorative materials, etc.