316 stainless steel, 18Cr-12Ni-2.5Mo Due to the addition of Mo, its corrosion resistance, atmospheric corrosion resistance and high temperature strength are particularly good, and it can be used under harsh conditions; excellent work hardening (non-magnetic). Equipment used in seawater, chemical, dye, papermaking, oxalic acid, fertilizer and other production equipment; photography, food industry, coastal facilities, ropes, CD rods, bolts, nuts. Chemical composition of 316 stainless steel: C≤0.08, Si≤1.00, Mn≤2.00, P≤0.035, S≤0.03, Ni:10.0-14.0, Cr:16.0-18.5, Mo:2.0-3.0. Mechanical properties of 316 stainless steel: tensile strength (Mpa) 620 MIN, yield strength (Mpa) 310 MIN, elongation (%) 30 MIN, area reduction (%) 40 MIN, density of 316 stainless steel 8.03 g/cm3, this value is generally used for austenitic stainless steel.Socket welding flange refers to the flange that the pipe end is inserted into the flange ring step and welded at the pipe end and the outside. There are two types: with neck and without neck. The neck pipe flange has good rigidity, small welding deformation, good sealing, and can be used in occasions with a pressure of 1.0~10.0MPa. The type B flange for containers is also a socket welding flange, which is used in occasions with high sealing requirements. When designing, the socket welding flange can be checked as an integral flange.