April 17, 2018 | Prototype Casting

Machined Parts Prototyping – Our Processes

In our previous post, we took the time to take a step back in favor of highlighting our variety of prototype casting services. In that post, we also took the opportunity to give our readers a little bit of a Protcast Inc. history lesson. From our humble beginnings in 1995 to present day, we’ve expanded in size and in the scope of our services and processes. From metal casting to tool cutting to CNC machining in Denver, we are the go-to resource for many folks and businesses looking for a reliable machine shop.

In today’s post, we are going to continue with our overview theme, this time shining the proverbial spotlight on the different processes we offer with regards to manufacturing the part in question. Whether it’s printed sand mold, die casting, aluminum heat treatment, machining, rapid investment casting, precision sand (or no-bake sand) casting, we are fully capable of manufacturing a wide range of parts. However, each process we employ has its own set of strengths and weaknesses. Of course, we are happy to walk through the advantages and drawbacks of each process as it relates to your particular project, but the following blog is intended to serve as a framework of understanding.

We hope that after reading this blog, you walk away with a working knowledge of what we can do for private parties and businesses — businesses that perhaps are much like yours. Keep reading if you are interested in learning more about our business that specializes in magnesium, aluminum, and zinc cast and CNC machined parts for aerospace, defense, medical, robotics, automotive, along with oil and gas industries!

Rubber Plaster Mold Casting

If you are interested in our services which produce a silicone master tool for your part, consider our rubber plaster mold casting. You’ll find that the silicone mold can be used to make hundreds of parts without any degradation. We recommend considering this process if your parts are cast from magnesium or aluminum.

Rapid Investment Casting

An affordable process, rapid investment casting is ideal for magnesium, stainless steel, aluminum, and zinc. It serves as a competitively-priced alternative to expensive parts. Another strength of our rapid investment casting services is that we can ship you a set figure of castings in two days or thereabouts!


Did you know we boast a full-line machine shop which sports 8 vertical milling machines in addition to a 3+2 axis milling machine? We can machine parts from post-machining castings to tight tolerances to stock “hogouts.” If those terms confuse you, don’t worry. Just give us a call.

Precision Sand Casting

“No-bake,” or precision sand is a fine grain sand which is blended with a two-part urethane binder in order to formulate sand castings. This has the net effect of larger castings with thick walls and roughly 200 microinch surface finish. Other advantages include the fact that precision sand casting has very few size limitations, achieves top mechanical properties, and superior surface finish and dimensional tolerances than green sand castings.

Printed Sand Mold Process

One of our more recent offerings, printed sand mold process uses 3D Printer technology to print sand mold onto a print bed. This effectively does away with the need for hard tooling. We can produce more complicated cores and undercuts with little fuss using our 3D printed sand mold process.

Permanent Mold Casting

We cut hard tools from steel or graphite as part of our permanent mold casting. The advantages of this process include durable tooling that produces thousands of parts, in addition to its consistent geometry. Suffice it to say that permanent mold casting is an oft-appropriate avenue between die casting and sand casting.

Die Casting

Speaking of die-casting, this process, simply put, involves cutting a hard tool from steel. This is a perfect option for many production-part-projects. It’s seen as a natural progression for RPM parts to move from prototyping and small volumes to production and higher volumes.

Aluminum Heat Treatment

In most cases, we can treat most aluminum castings to T6 condition in three days or less, upon receiving the parts. This treatment can handle parts up to 48” x 48” x 60”. That is the largest aluminum heat treatment option in the entire state of Colorado!

As always, feel free to reach out to us if you’d like to chat about which process is right for your own project!