Introduction
Micah Chaban, Founder and VP of Sales at RapidMade, has built his career around helping businesses navigate advanced manufacturing processes. His company specializes in precision CNC Machining, 3D printing, and thermoforming, working with industries ranging from aerospace and medical to industrial manufacturing and consumer products. With extensive knowledge of material science and production efficiency, Micah helps customers select the right metals and plastics to optimize cost, performance, and manufacturability.
In this conversation, Micah breaks down what makes a material easy—or difficult—to machine, how different metals and plastics compare in strength, cost, and workability, and what manufacturers should consider when choosing a material for precision machining.
Why does material selection matter so much in machining?
Material selection is everything. Machining is all about precision, repeatability, and durability, but not every material cuts the same way. Some are a dream to machine, cutting cleanly and efficiently, while others generate excessive heat, wear down tools, or warp under stress. If you pick the wrong material, you’re looking at longer cycle times, higher costs, and potential failures in real-world use.
Every material behaves differently under cutting forces. Metals like aluminum machine fast and with minimal tool wear, while stainless steel and titanium require specialized tooling and slower speeds to maintain accuracy. Plastics introduce their own challenges—some hold tight tolerances, while others melt, deform, or absorb moisture, affecting precision. The key is matching the material to the functional requirements of the part while keeping machining time and cost under control.
What are the most commonly machined metals, and how do they compare?
It depends on the industry and the application. We work with a variety of metals, but the most common are aluminum, stainless steel, carbon steel, and titanium. Each has its own strengths and machining challenges.
Aluminum is one of the best all-around materials for machining. It’s lightweight, corrosion-resistant, and easy to cut, which means fast cycle times and low tool wear. The most widely used grade, 6061 aluminum, is incredibly versatile, used in automotive, aerospace, and industrial applications. If a customer needs higher strength, we might recommend 7075 aluminum, which is much tougher but also harder to machine and more expensive.
Stainless steel is where things get trickier. It’s essential for medical, marine, and industrial applications because of its corrosion resistance and strength, but it’s tough on tools and generates significant heat during machining. 303 stainless steel is the easiest to machine, while 304 and 316 stainless steel offer superior corrosion resistance but work harden quickly, meaning they need slower speeds and sharp cutting tools.
Carbon steel is a strong, affordable alternative to stainless steel, used in machinery, tools, and industrial components. 1018 carbon steel is easy to machine, but if you need something stronger, 1045 carbon steel has better wear resistance—though it’s a bit harder to cut. One downside to carbon steel is that it rusts without protective coatings, so it’s not the best choice for applications exposed to moisture or chemicals.
Titanium is in a league of its own. It’s stronger than steel but 45% lighter, making it critical for aerospace, medical implants, and high-performance automotive parts. But it’s also one of the hardest materials to machine, requiring slow speeds, specialized tooling, and aggressive cooling to prevent work hardening. Grade 5 titanium (Ti-6Al-4V) is the most common because it balances high strength and moderate machinability, but it’s still significantly more expensive and more difficult to cut than aluminum or steel.
How do plastics compare when it comes to machining?
Plastics are completely different from metals when it comes to machining. While they’re generally easier on cutting tools, they can present their own challenges, like melting, warping, or absorbing moisture. We typically work with Delrin, Nylon, PTFE, and PEEK, depending on the application.
Delrin, also known as Acetal (POM), is one of the best machining plastics available. It’s strong, wear-resistant, and holds tight tolerances, making it a great choice for gears, bushings, and mechanical components. It cuts cleanly without melting, unlike some softer plastics.
Nylon is another popular option, especially for bushings and industrial parts. It’s impact-resistant and naturally lubricated, but it has a downside—it absorbs moisture, which can cause dimensional instability. Machining nylon requires sharp tools, low speeds, and cooling techniques to avoid melting and deformation.
PTFE, or Teflon®, is used for seals, gaskets, and chemical-resistant parts. It’s extremely slippery, non-reactive, and heat-resistant, but it’s also soft and difficult to machine with precision. Since PTFE deforms easily, you have to control machining parameters carefully to prevent warping.
PEEK is a high-performance plastic used in aerospace, medical, and high-end industrial applications. It’s one of the strongest, most heat-resistant plastics available, but it’s also abrasive and tough on cutting tools. Because of its high cost and machining challenges, it’s typically reserved for extreme applications where nothing else will work.
What should manufacturers consider when selecting a machining material?
The best approach is to balance cost, machinability, and performance. Some materials may be cheaper upfront, but if they increase machining time or cause excessive tool wear, they might end up costing more in the long run.
Aluminum is fast and affordable to machine, making it a great choice for most general applications. Stainless steel and carbon steel provide higher durability, but require slower machining speeds and tougher cutting tools. Titanium is only worth the cost if weight savings and strength are critical.
For plastics, Delrin is the easiest to machine, while PTFE and PEEK demand specialized machining techniques. If a plastic will be exposed to moisture, heat, or chemicals, those factors need to be considered as well.
It’s important to think about the full lifecycle of the part—not just the material cost, but also how machining time, tool wear, and post-processing will impact overall production expenses.
How can manufacturers get expert guidance on material selection for machining?
Material selection isn’t always straightforward. Even a small change in alloy, plastic grade, or machining parameters can make a huge difference in cost, performance, and production efficiency.
At RapidMade, we help businesses optimize machining materials and processes based on their application, budget, and production requirements. Whether it’s fast, cost-effective aluminum machining, corrosion-resistant stainless steel components, or high-precision plastic parts, we provide tailored solutions to maximize efficiency and durability.
For custom machining services and expert consultation, visit rapidmade.com or contact info@rapidmade.com.