1. Types and code 2. Chemical elements3. Mechanical property　　　　roughness, and features of stainless steel surface and application of composite plate
No. Types code USA AISI Instruction
1 Austenite OCr18Ni9 304 Used most often
2 OCr17Ni12Mo2 316 Used in coastline areas
3 Ferrite 1Cr17 430 Used for interior decoration

Types Types Types code Chemical elements %
C Si Mn P S Ni Cr Mo
1 OCr18Ni9 ≤0.07 ≤1.00 ≤2.00 ≤0.035 ≤0.030 8.00-11.00 17.00-19.00 --
2 OCr17Ni12Mo2 ≤0.08 ≤1.00 ≤2.00 ≤0.035 ≤0.030 10.00-14.00 16.00-18.00 2.00-3.00
3 1Cr17 ≤0.12 ≤0.75 ≤1.00 ≤0.035 ≤0.030 -- 16.00-18.00 --

Types Types Yield Strength
/Mpa 		Tensile Strength
/Mpa 		Elongation /% Rigidity Remarks
HRB HV
1 OCr18Ni9 ≥205 ≥520 ≥40 ≤90 ≤200 After solution
treatment
2 OCr17Ni12Mo2 ≥205 ≥520 ≥40 ≤90 ≤200
3 1Cr17 ≥205 ≥450 ≥22 ≤88 ≤200 Annealing state

Code Surface
types		 Surface
roughness
Ra(μ m)		 Surface features and application
of composite plate
Code Surface
types		 Surface
roughness
Ra(μ m)		 Surface features and application
of composite plate
1 2D(rolling 0.13—1.0 Half matte surface, even grey, low reflectivity, reflecting light
instead of image, fingerprint easy to be left. It is mainly used
for curtain wall and roof, especially roof near the airport, no
glaring, and not disturbing pilot’s sight.		 4 NO.3 polishing
surface 		0.25—1.1 Strong directivity, short parallel lines, repairing and hiding
tiny nick and defects. It is often used for memorial buildings.
2 2B(rolling 0.06—0.5 More glazed than 2D, high reflectivity, half matte grey,easy to
leaving fingerprint and difficult to remove it. It is used for curtain
wall and roof, pavement sunshade. It is not advisable for the
buildings viewed from short distance. 		5 NO.4 polishing
surface		 0.18—0.64 Soft, of directivity, short parallel lines, light reflectivity,
repairing and hiding tiny nick and defects. It is widely
used in construction, such as entrance doorway,
curtain wall, roof and storefront, etc.
3 Bright annealing
surface (BA) 		0.01—0.10 High reflectivity, like mirror surface, no clear polishing line, small
scratching can be removed by polishing. It is used for decorative
surface. Due to mirror surface plate effect and competitive price,
it is often used to replace mirror surface plate. 		6 NO.6 polishing
surface		   Satin surface with polishing brush and oil on NO .4 polishing
surface, with very small line, and soft appearance. Directional,
light scattering instead of
Code Surface
types		 Surface
roughness
Ra(μ m)		 Surface features and application
of composite plate
Code Surface
types		 Surface
roughness
Ra(μ m)		 Surface features and application
of composite plate
7 Capillary
crack 		0.14—0.2 Variety of NO.6 polishing surface, directional, small long
parallel lines, reflectivity higher than NO.4 polishing surface,
directional 		11 Resin coating   Half matte surface, even grey, low reflectivity, reflecting light
instead of image, fingerprint easy to be left. It is mainly used
for curtain wall and roof, especially roof near the airport, no
glaring, and not disturbing pilot’s sight.
8 NO.7 polishing
surface 		0.06—0.2 High reflectivity: mirror surface, tiny grinding texture
visible		 12 Aluminum tin alloy
plating coat 		  Composed of 80%-85% aluminum and 15%-20% tin,about 20U m thick of plating coat,it is mainly used for roof surface to reduce glistening .The plating coat looks very simlar to the lead roof after disturbance the wind and rain.
9 NO.8 polishing
surface 		0.02—0.10 Mirror surface, tiny grinding texture visible. It is used
for entrance gate.		 13 Other   High reflectivity, like mirror surface, no clear polishing line, small
scratching can be removed by polishing. It is used for decorative
surface. Due to mirror surface plate effect and competitive price,
it is often used to replace mirror surface plate.
10 Super NO.8
polishing surface
0.13—1.0 High luster mirror surface, grinding texture invisible.