Comparing Metal Fabrication Methods
With many options available for metal fabrications, it can be difficult to choose the best alloy processing method for your application. Precision casting is a reliable, cost-effective option for high-quality, high-volume cast metal components.
Our team at Aero Metals has developed helpful comparison charts, so you can assess the differences between investment casting and other metal fabrication methods. Contact us if you have any questions while deciding if investment casting is right for you.
Common Metal Casting Methods
Investment Casting vs. Die Casting
Die casting uses molten metal and requires tooling made of hardened tool steel, which causes start-up costs to be extremely expensive and lengthy. Tools wear quickly, requiring expensive refurbishments and replacements throughout the life of the tool or product lifecycle. Ferrous metals, like carbon steel and stainless steel, cannot be die cast, further limiting its usefulness.
Our investment casting methods inject wax into an aluminum cavity. Aluminum has a lower metal fabrication cost, is easier to cut, and less expensive to maintain. Using wax also is easier on tooling, allowing it to maintain consistent parts for many more uses. Investment casting allows for ferrous and non-ferrous metals (aluminum, brass, bronze, etc) to be cast.
| Investment Cast | Die Cast | |
| Design Freedom | Most | Most |
| Tolerance Control | Best | Best |
| Surface Finish | Good | Best |
| Metal Selection | Most | Few |
| Size Range | Average | Average |
| Volume Capability | All | High |
| Lead Time | Medium | Long |
| Tool Cost | Average | High |
| Unit Cost | Average | Low |
| Added Machining | Average | Low |
Investment Casting vs. Powder Metallurgy
The powdered metal process allows metal particles to fuse together without melting and thereby keeping their shape. Parts made from powder metallurgy can be very dense, which can be good or bad depending on applications. Mold creation for powder metallurgy is expensive, and there are limits to geometry complexity that investment casting does not encounter.
While the powdered metal process requires many different steps, investment casting methods can cut down labor time and offer one continuous part that provides a consistently clean look to the end user. Additionally, the reduction of labor time reduces lead times and the overall cost.
| Investment Cast | Powdered Metal | |
| Design Freedom | Most | Least |
| Tolerance Control | Best | Best |
| Surface Finish | Good | Best |
| Metal Selection | Most | Average |
| Size Range | Average | Small |
| Volume Capability | All | High |
| Lead Time | Medium | Medium |
| Tool Cost | Average | Average |
| Unit Cost | Average | Low |
| Added Machining | Average | Low |
Investment Casting vs. Metal Stamping
Metal stamping is a more primitive metal shaping method that uses a die and high pressure to shape metal into the desired parts. There is not much flexibility in the shape and thickness of the sheet with metal stamping. The greater the complexity of the part, the more additional components that must be added which raises the cost.
Metal stamping also produces a lot of waste, as there is a significant amount of unused scrap metal that results from a stamping project, much more than with investment casting methods. Investment castings reduce waste, labor time, and machine time, avoiding a costly metal fabrication process. Investment casting can also incorporate varying metal thicknesses and blind holes.
| Investment Cast | Stamping | |
| Design Freedom | Most | Average |
| Tolerance Control | Best | Best |
| Surface Finish | Good | Best |
| Metal Selection | Most | Average |
| Size Range | Average | Average |
| Volume Capability | All | High |
| Lead Time | Medium | Medium |
| Tool Cost | Average | High |
| Unit Cost | Average | Low |
| Added Machining | Average | Low |
Investment Casting vs. Metal Forging
Forging is a metal fabrication process that uses a massive hammer to push the material into the desired shape. This process requires extremely expensive tooling that often needs to be replaced. While forging produces high-strength parts, there is a heightened level of danger with forging. Specialty equipment also drives the cost of forgings higher. Many forgings need to be heavily treated after completion for hardness and machined due to a lack of tolerance holding.
The investment casting process requires less expensive equipment and is inherently less dangerous, allowing costs to remain lower. Investment castings also can hold much tighter tolerances, reducing the amount of machining typical to forgings.
| Investment Cast | Forging | |
| Design Freedom | Most | Least |
| Tolerance Control | Best | Poor |
| Surface Finish | Good | Average |
| Metal Selection | Most | Average |
| Size Range | Average | Average |
| Volume Capability | All | High |
| Lead Time | Medium | Long |
| Tool Cost | Average | Average |
| Unit Cost | Average | Average |
| Added Machining | Average | High |
Investment Casting vs. Permanent Mold
Permanent molds consist of mold cavities machined into metal die blocks which are designed for repetitive use. This process has a higher cost of tooling that requires a higher volume of castings in order to make economic sense. Permanent molds are also generally limited to the production of somewhat small castings of simple exterior designs.
Investment casting methods are suitable for either large or small quantities of parts, and these methods are also suitable for most ferrous and non-ferrous metals.
| Investment Cast | Permanent Mold | |
| Design Freedom | Most | Average |
| Tolerance Control | Best | Average |
| Surface Finish | Good | Average |
| Metal Selection | Most | Average |
| Size Range | Average | Average |
| Volume Capability | All | All |
| Lead Time | Medium | Medium |
| Tool Cost | Average | Average |
| Unit Cost | Average | Average |
| Added Machining | Average | Average |
Investment Casting vs. Plaster Molding
Plaster molding is a casting process with similarities to sand casting. Plaster molding delivers a smooth, as-cast finish, but it requires a minimum of a 1-degree draft. It is a more expensive process than permanent mold and sand casting, and this method may require the frequent replacement of plaster molding materials.
Investment casting offers flexibility in design and is a useful process for casting alloys that are difficult to machine. Investment casting methods also allow for complex shapes, intricate core sections, finer details, and thinner walls.
| Investment Cast | Plaster Mold | |
| Design Freedom | Most | Average |
| Tolerance Control | Best | Average |
| Surface Finish | Good | Average |
| Metal Selection | Most | Few |
| Size Range | Average | Average |
| Volume Capability | All | Low |
| Lead Time | Medium | Short |
| Tool Cost | Average | Low |
| Unit Cost | Average | High |
| Added Machining | Average | Average |
Investment Casting vs. Sand Casting
Sand castings are made by creating a negative in a bed of sand to create the cavity for casting. A sand shell creates a rough exterior to castings with a typical surface finish of 250 Ra as cast. Sand castings usually need extensive work afterwards to create a surface finish that is acceptable in most applications. They also can’t hold as tight of tolerances as investment castings and usually require more machining as well.
Investment casting uses a ceramic mold that can produce a much smoother finish, typically averaging 125 Ra surface finish as cast. Investment castings also greatly reduce the amount of machining that will be required after casting by holding a .005”/inch tolerance for the majority of the applications.
| Investment Cast | Sand Casting | |
| Design Freedom | Most | Average |
| Tolerance Control | Best | Poor |
| Surface Finish | Good | Poor |
| Metal Selection | Most | Most |
| Size Range | Average | Large |
| Volume Capability | All | All |
| Lead Time | Medium | Medium |
| Tool Cost | Average | Low |
| Unit Cost | Average | Average |
| Added Machining | Average | High |
Investment Casting vs. Metal Fabrication
Metal fabrications are metal structures produced by cutting, bending, and welding multiple pieces of material together. This method involves many steps and often results in a higher scrap rate. The increase in wasted materials, along with increased labor time, causes metal fabrications to be expensive and time-consuming.
A fine-tuned investment casting method produces reliable parts and consistently delivers a clean look to the end user. The reduction of labor time also reduces lead times and all applicable costs. Casting consistency can also lead to lower scrap rates, which can lower your overall metal fabrication costs even further.
| Investment Cast | Metal Fabrication | |
| Design Freedom | Most | Average |
| Tolerance Control | Best | Average |
| Surface Finish | Good | Poor |
| Metal Selection | Most | Average |
| Size Range | Average | Large |
| Volume Capability | All | All |
| Lead Time | Medium | Short |
| Tool Cost | Average | Low |
| Unit Cost | Average | High |
| Added Machining | Average | High |
Contact Aero Metals to Start Your Precision Investment Casting Project Today
We hope that this background information offers you a comparison when choosing your preferred metal fabrication method. Precision investment casting can save you time and money, providing a quality alternative to other processes.
Contact Aero Metals for more information on our metal fabrication investment casting methods, or request a quote today.
