ThePipingMart Blog Grades 403 Stainless Steel (UNS S40300) – Composition, Properties, and Uses

403 Stainless Steel (UNS S40300) – Composition, Properties, and Uses

403 Stainless Steel

403 stainless steel is an alloy with various elements, including iron, carbon, chromium, and nickel. It has excellent heat- and corrosion-resistance properties, making it perfect for multiple applications. In this blog post, we’ll explore the properties and uses of 403 stainless steel so you can decide whether or not it’s right for your project.

403 steel Material is highly resistant to staining and corrosion due to its high levels of chromium. This alloy also contains high amounts of nickel which makes it very durable. It can withstand extreme temperatures without becoming brittle or cracking. Additionally, because of its high levels of nickel, it only needs as much maintenance as other types of stainless steel.

What Forms is 403 Stainless Steel Available at Piping Mart?

  • 403 Stainless Steel Pipes
  • 403 Stainless Steel Tubing
  • 403 Stainless Steel Bolts
  • 403 Stainless Steel Channels
  • 403 Stainless Steel Bars
  • 403 Stainless Steel Nuts
  • 403 Stainless Steel Washer
  • 403 Stainless Steel Stud Bolts
  • 403 Stainless Steel Fasteners

403 Stainless Steel Chemical Composition

403 stainless steel has a unique composition, encompassing 14-16% chromium, 0.15% carbon, 0.6-0.75% manganese, and up to 10.5% nickel which contributes to its repeatable properties and outstanding mechanical strength along with impressive heat resistance while still being highly weldable.

Element Content (%)
Iron, Fe 86
Chromium, Cr 12.3
Manganese, Mn 1.0
Silicon, Si 0.50
Carbon, C 0.15
Phosphorous, P 0.040
Sulfur, S 0.030
Carbon, C 0.15

403 Stainless Steel Physical Properties

403 SS is a type of stainless steel, which has a number of desirable physical properties. It features high levels of corrosion resistance and ductility, making it useful in many industries that deal with acidic or corrosive chemicals. Its strength makes it perfect for use in heavy machinery, as well as providing insulation from extreme temperatures. Another important property of 403 stainless steel is its high level of electrical resistance and thermal conductivity, adding to its applications for electrical components used near heat sources. Lastly, due to its non-magnetic characteristics, this Inconel sheet is ideal for use in medical devices and settings where non-magnetic materials are required.

Properties Metric Imperial
Density 7.80 g/cm3 0.282 lb/in³

403 Stainless Steel Mechanical Properties

403 stainless steel is a highly corrosion-resistant alloy that is often used in the production of sheets. It has excellent mechanical properties, including good cold working characteristics and high strength. Through heat treatment, its strength and hardness can be further increased for use in applications such as food processing equipment, cutlery, surgical instruments, and pressure vessels. It also offers great resistance to oxidation at high temperatures along with low magnetic permeability. 403 stainless steel is also non-magnetic with excellent formability and weldability. In addition to inconel sheet production, it is well suited for many other industrial applications and provides the highest levels of performance in various extreme conditions.

Properties Metric Imperial
Tensile strength 485 MPa 70300 psi
Yield strength (@strain 0.200 %) 310 MPa 45000 psi
Fatigue Strength (annealed, @diameter 25mm/0.984 in) 275 MPa 39900 psi
Shear modulus (typical for steel) 76.0 GPa 11000 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30
Elongation at break (in 50 mm) 25.00% 25.00%
Izod impact (tempered) 102 J 75.2 ft-lb
Hardness, Brinell (converted from Rockwell B hardness) 139 139
Hardness, Knoop (converted from Rockwell B hardness) 155 155
Hardness, Rockwell B 80 80
Hardness, Vickers (converted from Rockwell B hardness) 153 153

403 Stainless Steel Thermal Properties

UNS S40300 is well-known for its excellent thermal properties – among the highest of any hardened steel. This makes it ideal for use in applications that require resistance to heat and oxidation at high temperatures. Its ability to rapidly dissipate heat can be further increased by adding a chromium or nickel alloy coating, allowing it to be used in even the most demanding environments. Not only does this material have great corrosion, wear, and thermal properties, but it is also extremely strong, making it suitable for range of industrial applications.

Properties Metric Imperial
Thermal expansion co-efficient (@0-100°C/32-212°F) 9.90 µm/m°C 5.50 µin/in°F
Thermal conductivity (@500°C/932°F) 21.5 W/mK 149 BTU in/hr.ft².°F

403 Stainless Steel Electrical Properties

403 stainless steel is an alloy commonly used for electrical installations due to its strength and resistance to corrosion. With a significantly high thermal conductivity, it excels in dissipating heat while maintaining consistent electrical properties. Inconel sheets, made from the same alloy, are even more resistant to oxidation at higher temperatures and can be formed into thin sheets with improved workability, making them ideal for any electronics that require durability in extreme conditions such as aerospace applications. 403 stainless steel will not let you down when you need an extra layer of protection for your electrical components.
The electrical properties of 403 stainless steel are resistivity – 740 x 10-6 Ω·m and electrical conductivity – 22% IACS.

403 Stainless Steel Equivalent

Equivalent materials to 403 stainless steel are given in the table below.

AISI 403 AISI 614 ASTM A176 ASTM A276 ASTM A473
ASTM A314 ASTM A479 ASTM A511 ASTM A580 DIN 1.4000
QQ S763 AMS 5611 AMS 5612 FED QQ-S-763 MIL SPEC MIL-S-862
SAE 51403 SAE J405 (51403)

403 Stainless Steel Specifications

403 Stainless Steel Seamless / Welded Pipes – ASTM A312

403 Stainless Steel Tubing / Welded Tubing – ASTM A269

403 Stainless Steel Bar / Rod – ASTM A276 / A479

403 Stainless Steel Forging – ASTM A182

403 Stainless Steel Sheet Plate – ASTM A240

403 Stainless Steel Welding Consumable – AWS A5.9

403 Stainless Steel Uses

Because of its durability and resistance to corrosion and staining, UNS S40300 is often used in medical equipment such as surgical instruments, syringes, and needles. It’s also popular in automotive and industrial manufacturing settings where strength and reliability are needed. Other common uses include kitchen appliances like cutlery and cookware and fasteners like screws and bolts.

403 Stainless Steel Corrosion Resistance

While 403 stainless steel is not as corrosion-resistant as other stainless steel types, such as 304, it has good resistance to atmospheric corrosion, fresh water, mild acids, and alkalis. It is not recommended in saltwater environments or highly acidic and oxidizing fluids.

403 Stainless Steel Heat Treatment

SS 403 is commonly hardened using heat treatment methods such as quenching and tempering. It can also be annealed to improve its ductility and toughness. Annealing should be done at temperatures ranging from 790-870°C, followed by air cooling.

403 Stainless Steel Machining

Machining 403 stainless steel can be challenging due to its high hardness. However, it can be accomplished using high-speed tool steels and carbide tools with a sharp cutting edge. It is recommended that the workpiece is rigidly held while machining to prevent deflection.

403 Stainless Steel Welding

403 stainless steel is weldable, but preheat and post-weld heat treatment is recommended to avoid cracking. It is important to note that 403 stainless steel has poor weldability compared to other stainless steel types.


403 stainless steel is an incredibly versatile alloy with many applications. Its heat- and corrosion-resistant properties make it ideal for use in medical settings, automotive industries, industrial manufacturing processes, and kitchen appliances like cutlery and cookware. It’s also incredibly strong, making it an excellent choice for fasteners like screws and bolts. Whether you’re looking for a metal that can withstand extreme temperatures or something that won’t corrode easily, 403 stainless steel may be just what you need!

Related Post