TIPS WITH TONY: Prototyping with Soft Metals

Soft metals — aluminum, magnesium, brass, copper — are available in different grades at Proto Labs depending on the 3D printing, CNC machining and injection molding service chosen. Quantities range from 1 to 5,000+ parts in 1 to 15 business days.

Aluminum engine bracket 3D printed through DMLS.

At Proto Labs, we use the industrial 3D printing process of direct metal laser sintering (DMLS) to build parts from soft (and hard) materials like aluminum.

DMLS-built aluminum provides parts with excellent strength-to-weight ratios, temperature and corrosion resistance, and provides good tensile, fatigue creep and rupture strength. With a tensile strength of 37.7 ksi (260 MPa) and a hardness of 47.2 HRB, for example, you are able to have parts produced in nearly any part geometry with features like internal channels or complex undercuts that can’t be manufactured through any other method. And, final parts are still up to 98% dense.

You can also get aluminum parts using CNC machining in 6061 and 7075 grades. 6061 can provide you with improved corrosion resistance and can be welded while 7075 provides you a part that has a higher tensile strength and is harder than 6061.

Do you need a prototype of an aluminum die-cast part? We can mimic aluminum die casting using our stereolithography (SL) process and SLArmor technology. SLArmor uses our DSM Somos (NanoTool) material, applying a nickel metal coating that gives the look and feel of metal without the added strength or weight.


Proto Labs offers molded and machined grades of magnesium that provide superior strength-to-weight ratios over steel and aluminum. Magnesium provides a weight savings around 25 percent over aluminum and 65 percent over steel. You now have two ways of producing low-volume part quantities similar to those from die-casting.

Molded magnesium is available in AZ-91 and machined magnesium in AZ31B, both of which are strong-yet-lightweight materials with RFI and EMI shielding commonly used for aerospace, automotive, military and electronic applications. Magnesium can oxidize or corrode if not protected, so secondary processes like anodizing (outside of Proto Labs) are recommended before parts are used in the assemblies.

Brass and Copper
Brass is a great material that can be used in corrosive environments; it is ductile but develops patina over time. Brass is used for applications like locks, gears, bearings, valves and electrical equipment. While copper may corrode if not protected, it can be used for electrical, plumbing components and heatsinks.

Brass is available in 260 (70/30) for milled parts and C360 for turned parts. Copper C101 is available for milled parts only and is currently not available for turned parts.

More Resources
For additional information on our full list of materials in 3D printing, CNC machining and injection molding, visit our materials section online or contact one of our customer service engineers at or 877.479.3680 with any additional questions you may have. We also have a free white paper on Rapid Manufacturing for Metals that offers a comprehensive look at both soft and hard metals.

Stay tuned for next week’s blog as we turn our focus on hard metal — steel, stainless steel — offerings at Proto Labs, which, like our soft metal selection, can be rapidly manufactured in quantities of 1 to 5,000+ parts.

This entry was posted in Tips with Tony and tagged , , , , by Tony Holtz. Bookmark the permalink.

About Tony Holtz

Tony is a technical specialist at Proto Labs with more than 10 years of experience ranging from CNC mill operator to mold designer to customer service engineer. While his formal education is in industrial machinery operations, he has extensive knowledge and experience in both traditional and advanced manufacturing processes and materials. Throughout his tenure at Proto Labs, Tony has worked with countless designers, engineers and product developers to improve the manufacturability of their parts.

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