ThePipingMart Blog Grades 347 Stainless Steel (UNS S34700) – Composition, Properties, and Uses

347 Stainless Steel (UNS S34700) – Composition, Properties, and Uses

347 Stainless Steel

If you’re in the market for a reliable, durable material that can withstand the test of time, then look no further than 347 stainless steel. This versatile material offers many properties, making it an ideal choice for many applications. Read on to learn more about what makes 347 stainless steel special and how it can help you with your projects.

What Forms is 347 Stainless Steel Available at Piping Mart?

  • 347 Stainless Steel Pipes
  • 347 Stainless Steel Tubing
  • 347 Stainless Steel Pipe Fittings
  • 347 Stainless Steel Bolts
  • 347 Stainless Steel Valves
  • 347 Stainless Steel Plates
  • 347 Stainless Steel Flnages

347 Stainless Steel Composition

SS 347 is an austenitic, chromium-nickel alloy with a composition of 18% chromium and 10% nickel. It offers good forming and welding characteristics along with excellent corrosion resistance in many corrosive environments. Due to its high chromium content, 347 stainless steel has superior pitting resistance compared to other steels in the 300 series. Its improved creep strength at elevated temperatures make it an ideal choice for applications requiring high temperature service.

Fe 68.0% Cr 17.0% Mn <=2.0% C 0.080% Si <=1.0%
Ni 11.0% S <=0.030% Nb+Ta 0.80% P <=0.045%

347 Stainless Steel Physical Properties

347 stainless steel is an material of grade 347, most known for its excellent oxidation and corrosion resistance. It also possesses great strength at high temperatures, making it ideal for many industrial applications where high-temperature environments exist. Additionally, 347 stainless steel has a high level of chromium and nickel content which makes it evenly resistant to oxidation and other atmospheric events at any given temperature. Furthermore, while 347 stainless steel are susceptible to some deformation when exposed to temperatures over 800°C, they still maintain excellent toughness throughout their lifespan.

Physical Properties
Density ( ) 7.93
Melting point (°C ) 1400-1425

347 Stainless Steel Mechanical Properties

UNS S34700 is an attractive choice for many applications because of its impressive mechanical properties. With significant resistance to dishing, slivering, and warping, 347 stainless steel provides excellent dimensional stability. Moreover, it has great strength and hardness values even at increased temperatures. In fact, the higher chromium and nickel content improves the overall ductility, allowing the stainless steel to flex slightly in parts that are repeatedly loaded. Of course, the incredibly resistant nature of this stainless steel also allows it to be welded without losing its strength and performance. This makes 347 stainless steel an ideal choice for a variety of engineering projects.

Mechanical Properties
Elongation at break ( % ) <60
Hardness – Brinell 160-190
Izod impact strength ( J.m-1 ) 20-136
Modulus of elasticity ( GPa ) 190-210
Tensile strength ( MPa ) 520-1100

347 Stainless Steel Properties

So what makes this type of steel so beneficial? For starters, it has excellent oxidation resistance, as well as superior corrosion resistance. It also has a high creep strength at elevated temperatures, which means it can handle extreme temperatures without deforming or cracking. Additionally, it has excellent weldability and good formability. Its tensile strength ranges from 90-120 ksi (620-830 MPa). In terms of composition, 347 stainless steel contains a maximum of 0.08% carbon, 17-19% chromium, 9-13% nickel, 2% manganese, 1% silicon, and traces of phosphorus and sulfur.

  • 347 stainless steel is an austenitic chromium-nickel stainless steel that contains columbium and tantalum.
  • 347 stainless steel has good corrosion resistance and is stabilized by adding columbium and tantalum.
  • 347 stainless steel is non-magnetic in the annealed condition but may become slightly magnetic in the cold-worked state.
  • The alloy has excellent resistance to intergranular corrosion in the as-welded condition and is not susceptible to weld decay.
  • 347 stainless steel has a high creep strength and can be used at temperatures up to 1500°F (816°C).

347 Stainless Steel Thermal Properties

Thermal Properties
Coefficient of thermal expansion ( x10-6 K-1 ) 16-18 @ 20-100 °C
Maximum use temperature in air ( °C ) 800

347 Stainless Steel Specifications

  • UNS S34700
  • AMS 5512
  • AMS 5646
  • ASTM A 269
  • ASTM A 276
  • ASTM A193
  • ASME SA 269
  • ASME SA 276

347 Stainless Steel Uses

Because of its impressive properties, there are many potential uses for this type of stainless steel. Some common applications include aircraft exhaust manifolds; power plant stacks; chemical processing equipment; food processing equipment; pressure vessels; heat exchangers; valves and fittings; condensers and evaporators; turbine blades and vanes; medical implants and prosthesis components; cookware and bakeware; marine hardware such as handrails or cleats; automotive trims and trim pieces such as wheel covers or hubcaps.
Moreover, due to its durability and excellent temperature resistance characteristics, it is also commonly used in cryogenic systems such as cryogenic storage tanks or cryogenic transportation containers.


347 steel Material is an incredibly useful material that offers numerous benefits for those looking for a durable alloy suitable for various applications in industries such as aerospace engineering, chemical processing plants manufacturing environments, or the automotive industry. With its high creep strength at elevated temperatures, its excellent oxidation resistance capabilities, and superior corrosion resistance properties, this type of steel is an attractive option when considering materials that will stand the test of time! Whether you need it for aircraft exhaust manifolds or medical implants, -347 stainless steel has your back! So if you’re looking for an alloy that won’t let you down – consider giving 347 stainless steel a try today! It just might be the perfect fit for your project needs!

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