416 (IC 416) Stainless Steel Investment Castings

304 stainless steel investment cast part

Most stainless steels, while hard and corrosion-resistant, are difficult to machine. One of the few exceptions is 416 stainless steel.

416 stainless steel is a free-machining alloy that possesses high strength and exceptional chemical resistance. 416 stainless steel investment castings are commonly used by manufacturers in the aerospace, medical, food processing, and defense industries due to their high strength-to-weight ratio and resistance to corrosion and chemicals.

Applications

Investment casting of 416 stainless steel can create parts with fine detail and intricate internal voids and cavities. This makes it a good choice in applications like valve bodies, provided they will not be used in applications with exposure to chlorides (for example, sanitary cleaning regimens) or high pressures.

416 stainless steel investment castings are generally used in applications such as:

  • Electric Motors
  • Fasteners
  • Knives
  • Pumps
  • Valves
  • Housings
  • Machine Components
  • Gears & Drive Components

Specifications

Barron Industries produces 416 (IC 416) investment castings to meet MIL-S-81591 (steel, investment castings, carbon, and corrosion-resisting) specifications for military and defense applications.

416 Stainless Steel Properties

Stainless steels get much of their corrosion resistance from chromium, but 416 balances this with a relatively high carbon content that results in a martensitic structure. Uncommon in stainless steel, this provides impressive levels of hardness and strength (maximized through further heat treatment) and machinability close to that of carbon steel.

Its chemical properties include:

Carbon (0.15% maximum), manganese (1.25% maximum), silicon (1% maximum), phosphorus (0.06% maximum), sulfur (0.15% maximum), and chromium (12 to 14%). The addition of sulfur contributes to the machinability of this alloy, and the absence of nickel is responsible for 416’s corrosion resistance being lower than other stainless steels.

Its specific mechanical properties are outlined in the table below:

ConditionTensile Strength (PSI)Yield Strength (PSI)% ElongationHardness
Hardened95-200,00075-160,0003-894Rb–45Rc

Advantages & Limitations of 416

The main characteristics of 416 that make it the alloy of choice for a wide range of applications are:

  • High Strength
  • High Hardness
  • Exceptional Heat Resistance
  • Good Corrosion Resistance
  • Good Machinability

It is important to note that 416 also has limitations that make it unsuitable for some applications. These are:

  • Vulnerable to Attack by Chlorides
  • Poor Weldability
  • Low Ductility
  • Can Corrode in Certain Marine Applications
  • Not Recommended for Some High-Pressure Applications 

Contact Barron Industries Today

Have questions? Barron Industries is ready to help. Founded in 1923, we’re a full-service manufacturer serving clients globally. We specialize in helping clients in the aerospace, defense, automotive, oil and gas, nuclear, medical, and commercial industries. To ensure quality, we’re also AS 9100- and ISO 9001-certified and accredited by Nadcap for non-destructive testing and welding.

If you would like to learn more about casting 416 stainless steel, please fill out our online form.