Investment Casting

Investment Casting of 400 Series Stainless Steels

Investment casting is a proven process that has been used by stainless steel casting manufacturers for a long histoty. The numerous benefits and advantages of investment casting for stainless steels that offers over other processes make it ideal for many industries and applications.

In this method, stainless steel parts are investment cast from molten metal. These metals are typically 300 series stainless-steels, 400 series stainless steels, precipitation hardening stainless steels, duplex stainless steels. What makes this process unique is how the stainless steel parts are formed. First, a wax version of the final product is made. This can be done with a 3D printer, a metal mold filled with hot wax, or a wax replica of the final product. If multiple parts need to be casted at once, the parts can be connected using wax runners and sprues to create a “tree”. Next, the molten stainless steel is poured into the molds. Once the mold is solidified, the ceramic mold is broken or destroyed to remove the parts.

Stainless steel casting offers excellent mechanical properties. Some cast stainless steel grades come with the added bonus of excellent corrosion resistance and some cast stainless steel grades are heat treatable allowing for further enhancement of mechanical and corrosion resistant properties. These are just some of the reasons why stainless steels are commonly used to manufacture a wide range of industrial and commercial investment casting products today. CFS Stainless Steel Casting Company has extensive experience manufacturing investment castings from a vast variety of stainless steel alloys in various shapes and sizes.

400 Series Stainless Steels for Investment Casting

Investment Casting of 400 Series Stainless Steels

Among all the stainless steels, 400 series stainless steels can also be adopted to suit investment casting technique. The 400 series stainless steels has an 11 percent chromium and 1-percent manganese increase, above the 300 series stainless steels. The 400 series is susceptible to rust and corrosion under some conditions. Heat-treating will harden the 400 series. The 400 series of stainless steels have higher carbon content, giving it a martensitic crystalline structure. This provides high strength and high wear resistance. Martensitic stainless steels aren’t as corrosion resistant as the austenitic types. 400 series stainless steels are frequently used for investment casting machine parts and valves for automotive and agriculture applications. We offer the following alloys:

  • 410
  • 416
  • 418
  • 420C
  • 430
  • 436
  • 440A
  • 440C


Considerations When Choosing Stainless Steel Investment Casting

Tooling Cost
The cost of manufacturing an injection tool for producing the pattern is relatively high. When talking about large volume productions, the cost savings from the manufacturing method will quickly replace the tool’s manufacturing costs. But with low volume productions, it may take years. However, in complex stainless steel pieces, investment casting may be the only possible economically sensible manufacturing method for even small series.

Size Restrictions
Although investment casting can be used to produce stainless steel components of varying magnitudes on a wide scale, the method also has an upper limit. In investment casting, this upper limit is lower than in many other casting methods, for example, sand casting. For larger stainless steel parts, sand casting is preferred.

The multi-step stainless steel casting process takes more time than other metal forming processes. But even though the casting process itself takes time, the overall turnover time to finished products is shorter because the need for post-casting machining is often low or nonexistent.


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