Titanium and stainless steel are two popular metal choices with wildly different mechanical properties. We’ll explore the differences, pros, and cons of both materials. Ultimately, you’ll understand which metal is the better choice for your next project, and how Rapid Axis can help.
What Is Titanium?
Titanium is a lightweight, high-strength metal that offers great corrosion resistance and one of the best commercially available strength-to-weight ratios. While it’s not used as commonly as stainless steel, our team at Rapid Axis regularly builds custom parts out of titanium.
On paper, titanium is about 45% lighter than stainless steel. When it comes to weight-sensitive applications like aerospace or high-performance automotive parts, it’s hard to find a better material than titanium.
The only way to get a lighter material that’s as strong, is to dive into high-cost specialty alloys, or work with carbon fiber that is incredibly difficult to manufacture. That’s why so many projects with tough requirements and specifications choose titanium.
Common Titanium Alloys in Machining
Generally speaking, you have three grades of titanium to choose from: Grade 2, Grade 5, and Grade 7.
- Grade 2 Titanium offers incredible corrosion resistance and good ductility. It is generally easier to machine.
- Grade 5 Titanium is the most popular alloy used in our shop. This alloy includes aluminum and vanadium, which translates to higher strengths with similarly low density. It is used heavily in aerospace, medical, mechanical, and defense projects.
- Grade 7 Titanium is a less common alloy that is used in specialized applications, like parts used in chemical processing facilities and marine parts. It is a “commercially pure” alloy with added palladium that yields great corrosion resistance and chemical resistance. It can be welded and bent easier, and offers much lower strength than Grade 5.
You’ll typically only choose Grade 2 or Grade 5, unless corrosion resistance is the driving factor for your project.
Pros of Titanium
The greatest advantage of titanium is its incredible strength-to-weight ratio. Titanium parts can support a lot of weight without weighing a lot themselves. This reduction in mass can improve efficiency, speed, fuel economy, and weight restrictions for parts across industries.
Another big benefit of titanium is its natural corrosion resistance. It can be exposed to wet and salty marine environments or chemical processing flows without corroding. In fact, titanium can last longer in these applications than stainless steel.
As a material, titanium boasts an impressive fatigue resistance, which means that you can cyclically load titanium parts and they will last longer before failing. This makes maintenance and part durability a breeze with the right titanium grade.
Cons of Titanium
The biggest downside of titanium is its cost. Not only is it more expensive to purchase the raw material, but there are added machining complexities that can also increase the cost of your parts. The machining complexities are due to the low thermal conductivity of titanium, so the parts don’t dissipate generated heat quickly. This causes faster tool wear and forces our machinists to be more careful about the speed and feed settings.
Luckily, our team at Rapid Axis has a ton of experience machining titanium, so these challenges are minimized as much as they can be through our expertise.
Shops with little titanium machining experience can accidentally work harden titanium if the tooling rubs instead of cutting cleanly. This increases surface hardness in localized areas, creating inconsistent passes and making the machining more difficult. In certain cases, the final part can have a non-uniform finish or thickness, which can cause parts to be out of spec.
Sticking with our team at Rapid Axis can avoid these issues and get you the best results for your titanium parts.
Want more CNC machining tips?
Grab our free CNC Machining Guide to learn how to avoid common pitfalls and optimize your design.
What Is Stainless Steel?
Stainless steel is a much more common metal, used in just about every industry you can think of. In just your home, you can find stainless steel parts in your kitchen, office, garage, laundry room, and closet.
By definition, stainless steel is an alloy of steel that contains at least 10.5% chromium, which creates a passive oxide layer on the outside surface of stainless steel, providing the corrosion resistance that this alloy is known for.
It’s worth mentioning that basic steel is not corrosion-resistant whatsoever, unlike pure titanium. The corrosion resistance is created through the addition of chromium.
As a material, stainless steel is easy to source and machine, offers great durability, is relatively inexpensive, and can be used in countless different applications.
Stainless steel is strong enough to be used in structural applications, often used as the go-to material for structural I-beams that support massive warehouses and industrial structures. At the same time, thin stainless steel sheet metal can be easily bent and welded together.
We can machine stainless parts much easier, with fewer considerations than titanium. It makes the manufacturing process more straightforward and easier to handle, usually resulting in lower manufacturing quotes.
Common Stainless Steel Alloys in Machining
Even though stainless steel itself is an alloy of steel, there are different configurations of stainless steel. Each configuration has a slightly different composition of elements, creating different mechanical properties.
- 304 Stainless Steel is arguably the most common grade. It combines good corrosion resistance with excellent formability, and impressive strength.
- 316 Stainless Steel introduces molybdenum, which makes this alloy more corrosion-resistant and easier to clean within cleanroom environments. It can be used in harsher chemical environments without corroding.
Other alloys are more specialized, so we typically reserve them for projects that have specific requirements that cannot be met by 304 or 316.
Pros of Stainless Steel
Stainless steel offers a lot of strength, versatility, and durability at a reasonable price. You can find sheets, plates, bars, tubing, and specialty geometries as stock options, making machining and assembly even easier.
Our machinists can handle stainless steel easily, and we can weld and bend stainless parts without any issues.
Since stainless steel is so strong, you can use it for load-bearing brackets and frames, or as the skin of an industrial machine.
Cons of Stainless Steel
Compared to titanium, stainless steel’s greatest drawback is its weight. It is significantly heavier, which leads to heavier parts and assemblies. This can be an issue for automotive or aerospace applications, where every pound matters.
Additionally, the corrosion-resistance of stainless steel can fall short over time. With exposure to moisture or chemicals, stainless steel can start pitting and failing as a result of corrosion. Meanwhile, titanium can survive the same environments without any corrosion.
Finally, you might need to do finishing steps like passivation to optimize the corrosion resistance of stainless steel parts, which adds time and money to each quote.
Titanium vs Stainless Steel
| Titanium | Stainless Steel | |
| Weight | ~45% lighter than stainless steel | Significantly heavier than titanium |
| Strength | Exceptional | Good |
| Corrosion Resistance | Exceptional | Good |
| Fatigue Resistance | Exceptional | Good |
| Machining Difficulty | More challenging due to low thermal conductivity and tool wear | Easier and more forgiving to machine |
| Cost | High | Low to moderate |
| Best For | Aerospace, medical, marine, chemical processing, weight-sensitive designs | Structural components, industrial equipment, general-purpose parts |
Choosing between titanium and stainless steel can be a simple choice once you know which material is better in certain situations.
If you need lifelong corrosion resistance without added finishing steps, then titanium is the better option.
For lightweight parts that offer great strength, titanium is the best choice.
If you need to save time and money on manufacturing, and your project doesn’t demand a lightweight material nor does it involve really harsh environments, stainless steel is the better option. It is a lower-cost, readily-available material that can be quickly and easily machined with our guys at Rapid Axis.
To put it really simply: stainless steel is the better option unless your project has strict requirements and demands that stainless steel can’t meet, then you’ll need to upgrade to titanium. You can consider stainless steel a “catch-all” material that excels in 90% of applications, and titanium is the much-needed upgrade to fulfill the needs of the other 10% of applications.
Conclusion
Whether you need the strength-to-weight ratio of titanium parts or the low-cost high-strength functionality of stainless steel, you can rely on Rapid Axis for all of your manufacturing needs. With plenty of CNC machinery in-house, we can fabricate, finish, and ship titanium or stainless parts right to your loading dock.
Our team has a ton of experience with most metals on the market, and we can work with specialty alloys. With more under one roof, you can get better results with Rapid Axis. Get a free quote and see the difference today.
