Investment Casting and CNC Machining Benefits and Process

Updated: Dec 7, 2018

AIM Contract Manufacturing uses two manufacturing processes to produce custom components for OEMs, ODMs, and other third parties: investment casting and CNC machining. The purpose of this article is to provide readers with an overview of each manufacturing process, the benefits, and the approach that AIM’s ISO 9001:2015 certified production partners have taken to produce intricate sub-level equipment components since 1984.

Investment Casting

Investment casting, also sometimes referred to as “lost wax casting,” is a manufacturing process that uses wax patterns to make expendable ceramic molds in which molten metal is poured. After the metal cools and solidifies within the pattern in which it was poured, the metal casting is removed from its pattern. The investment casting process has been in existence for over 5,500 years because of the benefits associated with the process, including:

  • Wide range of materials supported – many types of materials are used in the investment casting process. AIM represents facilities that support carbon steel, stainless steel, cast iron, alloy steel and duplex steel

  • Excellent surface finish – the expendable ceramic molds used in the wax patterns employed in the investment casting process produce a much smoother finish than other manufacturing processes

  • High degree of precision and superior tolerances – the investment casting process allows for the production of extremely intricate and complex parts. This high dimensional accuracy allows for relatively thin sections and higher tolerances, reducing the amount of finishing and machining processes in finished products

  • Lower lead time – the combination of automation of certain investment casting processes, coupled with less time spent on finishing and machining processes, enables investment casting facilities to get finished products to market faster

  • Broad range of intricate components produced – AIM’s investment casting and CNC machining production process enables it to produce sub-level equipment components in a wide range of industries and applications, including high temperature valves, high pressure valves, ball valves, gate valves, check valves, other valves, impellers, diffusers, pneumatic tools, automotive and fitness equipment, machinery and construction equipment, and medical equipment among many others

CNC Machining

CNC (computer numerical control) machining is a manufacturing process that makes use of computers to control tools operated by machines, including lathes, mills, routers and grinders. CNC machines are programmed with G-code machining language that controls features such as feed rate, coordination, location, and speed and is used for both metal and plastic parts. CNC machines take data from 2D or 3D CAD drawings and human operators oversee the testing and mass production processes. Like investment casting, many benefits are associated with CNC machining:

  • Wide range of products supported – CNC machining is a highly versatile manufacturing process; machines can be used to produce highly intricate components taken from just about any 2D or 3D CAD drawing.

  • Broad range of industries served – many industries need precision CNC machined parts, including oil and gas, marine automotive, food and beverage, aerospace, agriculture, construction, dental, medical, electronics, hospitality, fitness, tooling, all types of manufacturing, defense, and transportation among many others

  • Variety of materials supported – like the investment casting process, CNC machines work with a wide range of materials, including carbon steel, stainless steel, cast iron, alloy steel, duplex steel, titanium, aluminum, brass, copper, foam, plastic, fiberglass and wood among others

  • Equipment versatility – unlike manual operators, CNC machines are well-equipped to carry out many different operations depending on the specifications provided by buyers’, including but not limited to boring, contouring, cutting, drilling, engraving, facing, grinding, grooving, turning, threading, stamping, shearing, punching, milling, lathing, and knurling

  • High degree of precision – CNC machines make use of computer numerical codes to produce customized designs based on 2D and 3D CAD drawings, allowing for significantly higher accuracy when compared to human operators

  • Higher outputs and lower lead times – once product specifications have been inputted into a CNC machine, the machines are able to produce uniform products in large quantities around the clock and faster than manual operators

  • Lower costs – CNC machines require fewer personnel to operate at scale. Moreover, the high degree of efficiency and precision helps eliminate the need for rework, substantially lowering manufacturers’ materials and labor costs

Our Investment Casting and CNC Machining Approach

In an effort to balance price, quality, and speed to market, AIM Contract Manufacturing uses a combination of investment casting and CNC machining to maximize the overall benefits associated with both manufacturing processes. Our ISO 9001:2015 certified production partners utilize a 15-step production process to turn OEM, ODM, and other third parties’ designs into high-quality, affordable products.

1. Wax injection

2. Wax trimming

3. Pattern assembly

4. Slurry dripping

5. Drying

6. De-waxing

7. Shell mold sintering

8. Pouring and casting

9. Cooling

10. Knock-out

11. Sand abrasive

12. Removal and grinding

13. Forming

14. CNC machining and metal finishing processes

15. Final inspection

If you have a project that requires a well-established investment casting and/ or CNC machining partner that you would like to discuss with a sales representative, give us a call at 1-855-411-0404 or visit us at