ThePipingMart Blog Grades 305 Stainless Steel (UNS S30500) – Composition, Properties, and Uses

305 Stainless Steel (UNS S30500) – Composition, Properties, and Uses

305 Stainless Steel

UNS S30500 is an austenitic chromium-nickel alloy and one of the most popular types of stainless steel. It is known for its excellent corrosion resistance, making it a great choice for various applications and industries. In this blog post, we will cover all the essential information you need to know about 305 Stainless Steel, including its composition, chemical properties, physical properties, uses corrosion resistance, heat resistance, heat treatment, machining, and welding.

305 Stainless Steel Composition

305 Stainless Steel contains 17-19% chromium, 11-13% nickel, and 2-3% manganese. It also contains a small percentage of molybdenum and silicon, which helps improve its overall corrosion resistance. Additionally, it contains sulfur which improves its machinability. The chemical composition of 305 Stainless Steel makes it extremely resistant to oxidation in normal atmospheric conditions.

Element Content (%)
Iron, Fe 67
Chromium, Cr 18
Nickel, Ni 12
Manganese, Mn ≤ 2
Silicon, Si ≤ 1
Carbon, C 0.12
Phosphorous, P 0.045
Sulfur, S 0.030

305 Stainless Steel Chemical Properties

UNS S30500 provides superior corrosion resistance to a variety of corrosive media, making it a preferred material for many applications. It boasts excellent ductility and formability, as well as moderate strength. What’s more, 305 stainless steel can be easily soldered and welded to create nearly any shape imaginable. Its superior resistance to both chlorides and mild alkalis makes it suitable for exposure to industrial environments, while its low carbon content offers better resistance to carbide precipitation during welding. With its wide range of advantageous chemical properties, 305 stainless steel has become the go-to choice for an array of manufacturing needs.

305 Stainless Steel Mechanical Properties

UNS S30500 is austenitic stainless steel that can have excellent mechanical properties when compared to other materials. It contains a higher level of chromium and nickel elements, which allows for greater corrosion resistance than other austenitic stainless steels. In addition, 305 stainless steel features high strength and good formability, making it an excellent choice for many engineering applications. With its high ductility and toughness, this type of stainless steel is perfect for high-pressure environments like those found in power generation, petrochemical and oil & gas applications. From bridges to chemical tanks, the corrosion-resistant qualities of 305 stainless steel make it an indispensable material within the industry.

Properties Metric Imperial
Tensile strength, ultimate 585 MPa 84800 psi
Tensile strength, yield (@0.2%) 260 MPa 37700 psi
Modulus of elasticity 193 GPa 28000 ksi
Shear modulus 86 GPa 12500 ksi
Elongation at break (in 50 mm) 50 50
Hardness, Brinell 80 80
Hardness, Knoop (converted from Brinell hardness) 97 97
Hardness, Rockwell B (converted from Brinell hardness) 45 45
Hardness, Vickers (converted from Brinell hardness) 82 82

305 Stainless Steel Physical Properties

UNS S30500 had a good combination of strength and ductility when cold worked. It has a tensile strength of 75KSI min (515MPa) with an ultimate elongation rate of 34%. Its hardness is usually measured using the Rockwell B scale and can range from 95B to 105B depending on how much cold work has been done on the metal. Its magnetic permeability is low due to its high nickel content, which makes it nonmagnetic after annealing or welding.

Properties Metric Imperial
Density 8 g/cm3 0.289 lb/in³
Melting point 1454°C 2650°F

305 Stainless Steel Thermal Properties

Properties Metric Imperial
Thermal expansion co-efficient (@0-100°C/32-212°F) 17.3 µm/m°C 9.61 µin/in°F
Thermal conductivity (@0-100°C/32-212°F) 16.3 W/mK 113 BTU in/hr.ft².°F

305 Stainless Steel Equivalent

AMS 5514 ASTM A240 ASTM A478 QQ S766
AMS 5686 ASTM A249 ASTM A492 DIN 1.4303
ASME SA193 ASTM A276 ASTM A493 UNI X 8 CrNi 19 10
ASTM A167 ASTM A320 (B8P, B8PA) ASTM A580 SAE 30305
ASTM A193 (B8P, B8PA) ASTM A368 DIN 1.4303 SAE J405 (30305)
ASTM A194 (8P, 8PA) ASTM A473 QQ S763

305 Stainless Steel Uses

Due to its excellent corrosion resistance in both freshwater and saltwater environments, 305 Stainless Steel is widely used in marine applications such as boat fittings and hardware as well as mild industrial applications like food processing equipment and light fixtures. It can also be used for decorative purposes such as kitchen backsplashes or outdoor accents thanks to its attractive finish and durability when exposed to moisture or salt air environments.

Corrosion Resistance

305 stainless steel is often considered for its strong corrosion resistance capabilities. Hot and cold rolled 305 stainless steel provides superior protection against oxidation, making it the ideal choice for applications in harsh industrial environments or those with high exposure to the elements. Additionally, this type of stainless steel boasts excellent formability and weldability compared to other grades of steel, so it’s a perfect option when larger projects require specific shapes or sizes. Known as an austenitic chromium-nickel alloy steel grade, 305 stainless plays a key role in many industries ranging from automotive manufacturing to marine applications. All things considered, its corrosion-resistant qualities make it a top choice for many engineering needs.

Heat Resistance

305 Stainless Steel has excellent heat-resisting properties making it suitable for use in applications that require exposure to extreme temperatures or where there’s a risk of oxidation or scaling at elevated temperatures up to 1500°F (816°C). It does not respond well to hardening by heat treatment but can be hardened by cold working due to its higher levels of carbon compared to other 300 series stainless steels, such as 304 SS, which increases its strength without sacrificing any formability or ductility. Heat-treated 305 stainless steel should be done slowly at temperatures between 1450-1550°F (790-845°C).

Heat Treatment

305 stainless steel is a type of austenitic stainless steel that has excellent corrosion resistance and strength. Heat treatment of 305 stainless steel involves subjecting it to high temperatures for a short period, allowing it to cool rapidly, and then performing a stress relief process at a very high temperature. During heat treatment, the microstructure of 305 stainless steel changes which imparts superior properties like wear resistance, hardness and ductility. By controlling the heat-treatment process, the desired properties can be achieved – making this alloy suitable for various applications such as rocket engine parts, nuclear power plants and aerospace industry components. All in all, heat treatment of 305 stainless steel is essential for ensuring its longevity and performance in extreme conditions.


305 stainless steel can be machined using conventional techniques similar to those used with other 300 series austenitic stainless steels due to its higher levels of carbon which improves cutting speeds while still providing good surface finishes at slow speeds without too much power input required during machining operations. Its higher levels of carbon also make it suitable for welding, although preheating may be necessary before welding depending on the application requirements since this type of stainless steel tends to lose some ductility when heated above 600°F (316°C). The best type of filler metal that should be used with 305 stainless steel is 309L since it provides better corrosion resistance than 308L while still providing good mechanical properties after welding operations are completed.


Welding 305 stainless steel can be complicated, given its hardness. Although this type of steel is extremely corrosion-resistant, it also produces fractures more easily when being welded than other materials. To ensure a successful weld, it’s important to have the correct tools and equipment for the job. An argon gas mixture is usually necessary to help shield the welding arc from oxidation or contamination, as well as special nonmagnetic clamps to secure the material in place during welding. With the right measures taken, an experienced welder can weld 305 stainless steel with relative ease and expertise.


Overall, 305 Stainless Steel is an excellent choice for various applications that require exceptional corrosion resistance in both freshwater and saltwater environments as well as excellent heat-resisting capabilities up to 1500°F (816°C). It had a good combination of strength and ductility when cold worked, making it suitable for many different types of machining operations as well as being easy enough for welding with the right filler metal selection. With all these advantages combined together with an attractive finish that makes it suitable for decorative purposes, this type of stainless steel should definitely be considered if you are looking for an all-around versatile material that can handle almost any environment or task you throw at it!

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