After 304, this is the most common stainless steel on the market. Again it is an austenitic grade with the addition of 2-3% molybdenum which further improves corrosion resistance. It is often referred to as a marine grade stainless steel because of its effective resistance to chloride corrosion in comparison to other stainless steel grades.  The material has superior welding and forming qualities. Grade 316 will require post-weld annealing to promote maximum corrosion resistance, though this is not necessary if Type 316L is used.  Origins from the Paper Industry The steel was initially produced for the paper producing industry as it has been shown to be highly resistant to the sulphur compounds used in paper processing.  Typical applications for this material are now widespread due to its superior corrosion resistance properties when compared to Grade 304. Type 316 stainless can be found in heat exchangers, pharmaceutical equipment, dairies and breweries, marine fittings, coastal architectural fascia and fittings and in food preparation areas.  Product Range 316 & 316L steel plate and pipes have common properties and are often stocked with Dual Certification, where it is determined that both have properties and composition which comply with both steel types. Type 316H is excluded from this scenario by virtue of the fact that unlike 316 & 316L, 316H is engineered to work in elevated working temperatures.   Product Range Specifications: ASTM A/ASME SA213/A249/A269/A312/A358 CL. I to V ASTM A789/A790 Sizes (Seamless): 1/2" NB - 24" NB Sizes (ERW): 1/2" NB - 24" NB Sizes (EFW): 6" NB - 100" NB      Wall Thickness available:    Schedule 5S - Schedule XXS (heavier on request) Other Materials Testing:    NACE MR0175, H2 SERVICE, OXYGEN SERVICE, CRYO SERVICE, etc. Dimensions:    All Pipes is manufactured and inspected/tested to the relevant standards including ASTM, ASME and API etc. Background of 316 Stainless Steel Pipes & Tubes Grade 316 is the standard molybdenum-bearing grade, second in importance to 304 amongst the austenitic stainless steels. The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments. It has excellent forming and welding characteristics. It is readily brake or roll formed into a variety of parts for applications in the industrial, architectural, and transportation fields. Grade 316 also has outstanding welding characteristics. Post-weld annealing is not required when welding thin sections. Grade 316L, the low carbon version of 316 and is immune from sensitisation (grain boundary carbide precipitation). Thus it is extensively used in heavy gauge welded components (over about 6mm). Grade 316H, with its higher carbon content has application at elevated temperatures, as does stabilized grade 316Ti. The austenitic structure also gives these grades excellent toughness, even down to cryogenic temperatures. Composition of 316 Stainless Steel Pipes & Tubes    Table 1. Composition ranges for 316 grade of stainless steels. Grade   C Mn Si P S Cr Mo Ni N 316 Min - - - 0 - 16.0 2.00 10.0 - Max 0.08 2.0 0.75 0.045 0.03 18.0 3.00 14.0 0.10 316L Min - - - - - 16.0 2.00 10.0 - Max 0.03 2.0 0.75 0.045 0.03 18.0 3.00 14.0 0.10 316H Min 0.04 0.04 0 - - 16.0 2.00 10.0 - max 0.10 0.10 0.75 0.045 0.03 18.0 3.00 14.0 - Mechanical Properties of 316 Stainless Steel Pipes & Tubes    Table 2. Mechanical properties of 316 grade stainless steels. Grade Tensile Str (MPa) min Yield Str 0.2% Proof (MPa) min Elong (% in 50mm) min Hardness Rockwell B (HR B) max Brinell (HB) max 316 515 205 40 95 217 316L 485 170 40 95 217 316H 515 205 40 95 217    Note: 316H also has a requirement for a grain size of ASTM no. 7 or coarser. Physical Properties of 316 Stainless Steel Pipes & Tubes    Table 3. Typical physical properties for 316 grade stainless steels. Grade Density (kg/m3) Elastic Modulus (GPa) Mean Co-eff of Thermal Expansion (µm/m/0C) Thermal Conductivity (W/m.K) Specific Heat 0-1000C (J/kg.K) Elec Resistivity (nΩ.m) 0-1000C 0-3150C 0-5380C At 1000C At 5000C 316/L/H 8000 193 15.9 16.2 17.5 16.3 21.5 500 740 Grade Specification Comparison of 316 Stainless Steel Pipes & Tubes    Table 4. Grade specifications for 316 grade stainless steels. Grade UNS No Old British Euronorm Swedish SS Japanese JIS BS En No Name 316 S31600 316S31 58H, 58J 1.4401 X5CrNiMo17-12-2 2347 SUS 316 316L S31603 316S11 - 1.4404 X2CrNiMo17-12-2 2348 SUS 316L 316H S31609 316S51 - - - - - Note: These comparisons are approximate only. The list is intended as a comparison of functionally similar materials not as a schedule of contractual equivalents. If exact equivalents are needed original specifications must be consulted. Corrosion Resistance of 316 Stainless Steel Pipes & Tubes Excellent in a range of atmospheric environments and many corrosive media - generally more resistant than 304. Subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above about 600C. Considered resistant to potable water with up to about 1000mg/L chlorides at ambient temperatures, reducing to about 500mg/L at 600C. 316 is usually regarded as the standard “marine grade stainless steel", but it is not resistant to warm sea water. In many marine environments 316 does exhibit surface corrosion, usually visible as brown staining. This is particularly associated with crevices and rough surface finish. Heat Treatment of 316 Stainless Steel Pipes & Tubes     Solution Treatment (Annealing) - Heat to 1010-11200C and cool rapidly. These grades cannot be hardened by thermal treatment.