What Is Aluminum?

Aluminum is a low-cost, lightweight metal that has incredible machinability, weldability, and good corrosion resistance. Pure aluminum is really soft, but alloyed aluminum is stronger and more durable. 

With a density roughly 60% lower than titanium, aluminum is the much lighter option. If your project demands a lightweight material but doesn’t require excessive strength, then aluminum might be the no-brainer option.

Aluminum also has great thermal and electrical conductivity, and it’s used in heat sinks and electronic housings. Since aluminum is non-ferrous, you won’t have to worry about its interaction with electronic or magnetic fields.

Aluminum is one of the less expensive metals that can be CNC machined, bent, welded, and assembled.

Common Aluminum Alloys in Machining

Aluminum can be found in a lot of different alloys, which are combinations of aluminum with other elements. With dozens of alloys to pick from, you can fine-tune the mechanical properties that you’re looking for.

Although you can find aluminum alloys ranging from 1000 to 7000 series, the 6000 series is definitely the most common. This series adds magnesium and silicon to the aluminum base, creating a strong, versatile, corrosion-resistant, easily machinable, durable alloy.

6061 aluminum is an incredibly common alloy that combines these favorable mechanical properties with the ability to easily machine, weld, bend, and manufacture the parts.

Pros of Aluminum

Aluminum is a great material choice for a lot of different industries. You can find aluminum blocks, bars, sheets, plates, and structural shapes to start with, potentially minimizing the machining required. In addition, stock aluminum pieces are very affordable, and machining is quick and easy. This results in lower manufacturing quotes and more money in your pocket.

We can use aluminum in rapid manufacturing cycles, since it deals with heat well and dissipates it quickly. Often, this translates to lower turnaround times and quicker manufacturing. 

6061 aluminum can be anodized, powder coated, painted, and more. These finishing steps can refine how your parts look, ensuring a uniform finish that matches your branding or required aesthetics. 

Since aluminum is so readily available, we might have the correct stock piece in our inventory, so we can start working on your projects sooner.

Cons of Aluminum

The biggest limiting factor for aluminum is its ultimate strength, the total amount of force that can be supported before the part catastrophically fails. 6061 aluminum has an ultimate tensile strength of 310 MPa, and Grade 5 titanium’s is 1,100 MPa, so aluminum offers about 1/3 the total strength of titanium. This can be a decision-making factor for many projects that require parts to support heavy loads.

Another thing to consider is that aluminum starts to fail sooner in a high-temperature environment. While aluminum has decent thermal properties, they pale when compared to titanium’s.

Another drawback of aluminum is that it’s a softer metal, so surface imperfections happen quicker. Aluminum is more susceptible to surface wear, scratches, dents, and dings. You’ll have to worry about aesthetic imperfections as well as failure due to high-friction applications. Anodizing can help with some added durability.

What Is Titanium?

Titanium is a high-strength, lightweight metal that is incredibly corrosion-resistant and very strong. It is significantly more expensive than aluminum, but it also offers mechanical properties that are significantly better.

With a lower density and much higher strength, titanium has one of the best strength-to-weight ratios for any stock metal.

You’ll find titanium used across industries, especially where engineers want to minimize overall weight without sacrificing the strength of the part.

Common Titanium Alloys in Machining

Although you can find a few different grades of titanium on the market, the two most common options are Grade 2 and Grade 5.

• Grade 2 Titanium is easier to machine and has better corrosion resistance. This is the better option for applications in high-moisture environments.
• Grade 5 Titanium is the more popular titanium alloy. It has a higher strength and low weight, making it a good choice for aerospace and defense projects. Typically, this is the alloy of titanium that people think about using for projects, unless there are specialized requirements. 
• Grade 7 Titanium is reserved for applications that involve regular exposure to moisture or chemicals. It is a commercially pure alloy that includes palladium for incredible corrosion and chemical resistance. However, Grade 7 is weaker than Grade 5, so it shouldn’t be used for structural parts.

Pros of Titanium

The major benefit of titanium is its strength-to-weight ratio. Titanium can handle a lot of weight without weighing a lot, so you can create structural parts that weigh a fraction of what a steel or aluminum part would weigh. This reduction of mass is a game-changer for projects that have strict mass requirements or need to optimize the performance of a vehicle or assembly. 

In addition, titanium is naturally corrosion resistant. Titanium parts are known for long-term durability, making maintenance and swapping parts more infrequent throughout the lifetime of your parts. 

With its impressive strength, Grade 5 titanium parts have great fatigue resistance and resistance to failure due to cyclical loading.

Cons of Titanium

A major drawback of titanium is that it is significantly more expensive than aluminum. Not only is the raw material more expensive, but it can be harder to source in different sizes, and the machining is more difficult, so we have to charge more for machining titanium parts as compared to aluminum parts.

The big difference is the low thermal conductivity of titanium: since the heat doesn’t dissipate nicely, the machines’ tooling wears more quickly, and the machinists need to use slower machining speeds to create high-quality parts. The benefit of choosing Rapid Axis instead of a shop that isn’t familiar with titanium is that we already know the perfect machine settings and how titanium reacts. Using an inexperienced shop can lead to even bigger and more expensive issues during machining. 

Aluminum vs Titanium: Key Differences

Although titanium and aluminum are relatively similar on paper, titanium pulls ahead in almost every category. Of course, there’s a big price difference that goes along with these improved mechanical properties. 

Titanium is a lot stronger than aluminum, and it can be cyclically loaded longer before failing, making titanium the better option in structural parts.

Aluminum is more readily available, comes in more stock shapes, and is much easier to machine and more affordable. For larger projects, the machining turnaround time and cost differences will really stand out between aluminum and titanium. 

Applications of Aluminum vs Titanium in Key Industries

In the aerospace industry, both materials are incredibly common. Aluminum is a great general use metal that doesn’t weigh much and is inexpensive to purchase and machine. You can find it used in interior components and even structural panels. Titanium is used in larger parts or areas where weight consideration has a big impact on the functionality of the aircraft. 

Medical devices tend to use aluminum for equipment housings and various components. Titanium is used for implants due to its biocompatibility, corrosion resistance, and durability. If you know someone who recently had a knee, shoulder, or hip replacement, there’s a very good chance their new joint is titanium. 

Automotive companies tend to stick with aluminum (or steel) for consumer vehicles. Battery enclosures, framework, body panels, and suspension components rely heavily on aluminum since they can be machined easily and are affordable. Titanium is reserved for high-performance vehicles to reduce weight and optimize the mechanical performance of the cars.

Which Metal Should You Choose?

It might seem that titanium and aluminum are like-for-like replacements of one another. They are both lightweight metals that can handle weight, and both options are used across industries for similar parts. However, the two metals can’t be compared that way.

Titanium is the more expensive, more durable, stronger older brother to aluminum. In our experience, titanium should only be reserved for projects that need the added mechanical benefits of titanium; whether that’s the increased ultimate strength, better corrosion resistance, or biocompatibility that titanium offers.

In all other cases, aluminum or steel should be used. Aluminum is a fantastic general use metal that you can use for parts that don’t have specific strength requirements. For many engineers, aluminum is the default metal unless the project demands something that aluminum can’t handle.

By structuring your projects this way, you’ll save a ton of time and money in the machine shop. It’s no exaggeration that an aluminum part can be 30 times less expensive than a titanium part, and that rift only gets bigger as you look at larger and more complicated parts.

Conclusion

The good news? Our team at Rapid Axis has extensive experience with both aluminum and titanium. With common alloys in our warehouse, we can get started on your project quicker and offer realistic timelines for every part. We’ve fabricated countless aluminum and titanium parts during our decades in business, and we are confident that we can help with your upcoming project.

In addition, we offer a number of finishing operations that can maximize the functionality of your parts. From anodizing to powder coating and polishing, you can get the most out of your parts when you choose Rapid Axis.

Reach out to our expert machinists today to see which material is right for your next project. Get a free quote and get started with Rapid Axis. 

With lots of experience with both options, our expert machinists are here to describe the differences between steel and aluminum, and which option is right for you.

What Is Steel?

Steel is a combination of iron and carbon, plus a few other added elements. Steel can be alloyed with elements such as chromium, nickel, molybdenum, manganese, or vanadium to fine-tune the mechanical properties you get as a result.

Within the world of steel, there are various different options: 

• Carbon steel is an affordable, strong type of steel that is used for structural and high-wear parts.
• Alloy steel contains multiple different elements, and it’s used in very similar applications as carbon steel.
• Stainless steel contains at least 10.5% chromium, making an oxide layer that prevents corrosion. 

Through the right combination of added elements, steel can change its hardness, wear resistance, corrosion resistance, and strength.

In general, steel is a stronger metal than aluminum, and it weighs more.

Pros of Steel

Steel is a strong metal, often used in industrial and structural applications to support multiple tons of weight. In addition, steel is highly durable; the same part can last for a long time before failing, and it requires less maintenance to upkeep a steel part.

Cons of Steel

The biggest drawback of steel is its weight. It is around three times heavier than aluminum, which can be a disaster for projects that have low weight allowances. Using steel on a vehicle means higher strength but more weight, hurting the fuel efficiency and performance of the vehicle.

Another potential downside of steel is that it is magnetic, since it contains iron. 

While steel is easier to weld than aluminum, it can be more difficult to machine. We have to be careful with our feed and speed settings to avoid potential work hardening of steel while CNC machining it. 

Unless coated, most steels will corrode over time. This only gets worse when steel is exposed to wet or salty conditions.

What Is Aluminum?

Aluminum is a lightweight, non-ferrous metal that has an impressive strength-to-weight ratio. Aluminum is naturally corrosion resistant, and doesn’t require additional alloying or finishing steps to achieve this.

Pure aluminum is pretty useless in most industries, so a vast majority of aluminum we work with is an alloy. 6061 is the most common aluminum alloy, and it boasts a nice combination of strength, durability, low weight, corrosion resistance, and ability to be machined, welded, and bent without any issues.

Aluminum is also great at dissipating heat and managing thermal energy.

Pros of Aluminum

Aluminum is a great metal across the board. It has good corrosion resistance, thermal resistance, and electrical conductivity. Aluminum is lightweight and easy to use in manufacturing, so many engineers use it as their go-to metal in most projects.

When you want to cut weight with a metal part, aluminum is the most affordable way to do so.

Additionally, aluminum is a versatile material that can be used in countless applications and industries. It’s hard to think of a single industry that doesn’t use some amount of aluminum, and it’s easy to think of a handful that almost exclusively use aluminum. 

Cons of Aluminum

The biggest drawback of aluminum is its inability to handle heavy weights. It fails much sooner than steel, so it’s not a good idea to use aluminum for structural members. In cyclic loading, aluminum will fail before a steel part.

Additionally, aluminum loses strength more quickly in elevated temperatures, so it’s not a good choice for high-temperature operations. 

Steel vs Aluminum in CNC Machining & Fabrication

From a machining perspective, there’s no problem with using either steel or aluminum. Our CNC machines and machinists have no issues running either material. However, aluminum does tend to be easier and faster to cut since we can use higher speeds due to aluminum’s ability to dissipate heat well.

As far as surface finishes, aluminum gets a smooth finish quicker since it’s a softer material, and we might have to do post-processing on a steel part to achieve the same finish. 

To meet really tight tolerances, steel is a little easier since it is stiffer, making it easier to maintain dimensional stability. But again, both materials are fine options and we can make high-precision steel or aluminum parts.

In general, fabrication for both steel and aluminum poses no issues for our team at Rapid Axis. The only time things get complicated is if you opt for a specialty alloy that meets the needs of your project. Even then, we can handle the fabrication.

Choosing Between Steel and Aluminum

Choosing between steel and aluminum tends to be tricky. Both of these are versatile, readily-available, super ubiquitous materials. In most applications, you can use either material and it will work.

Broadly speaking, aluminum is the better option if you want some added corrosion resistance, you don’t have to worry about heavy loads, and you want to save a little bit of money on material and manufacturing costs.

Steel is the better option if you want a stronger part that lasts longer, and you don’t mind choosing the more expensive stainless steel alloy, or using powder coating to achieve corrosion resistance.

Conclusion

Steel and aluminum are both really popular metals that play major roles in industries across the globe. Our team at Rapid Axis can help you understand which choice is perfect for your next project, and we’re always here to explain the differences between these two metals. 

Luckily, our expert machinists and fully-equipped machine shop can handle almost any steel or aluminum project you have for us. As manufacturing experts, we’ve created countless steel and aluminum parts, and we have the background required to achieve great results.

You can get a free quote from us today and learn why you should trust Rapid Axis to be your manufacturing partner. 

What Is Alloy Steel?

By definition, alloy steel is the combination of carbon and iron (steel), and added elements to achieve specific mechanical properties. For example, one alloy of steel might be really easy to weld, another might be super strong, and a third option might be super inexpensive. It all depends on which elements are added and how much of each element is present.

Chromium increases hardenability and wear resistance. Nickel improves toughness and impact resistance. Molybdenum enhances strength at elevated temperatures and reduces brittleness. Vanadium refines grain structure and increases fatigue resistance.

Low-alloy steels have less than 5% of added elements, and they offer better strength.

High-alloy steels have more added elements, and they’re more specialized.

Pros of Alloy Steel

Alloy steel is a more affordable option, and it is often used in structural or high-strength parts. They can be heat treated to be even harder and stronger, as needed.

Alloy steel is also very fatigue-resistant, so alloy steel can be used for gears that are cyclically loaded without failing. 

The big benefit of alloy steel is that it’s inexpensive to source and manufacture, so you can save money on your parts if they don’t need to be corrosion-resistant. 

Cons of Alloy Steel

The major downside of alloy steel is that it isn’t corrosion-resistant. These parts are very susceptible to rusting, unless they’re powder coated and maintained over time. 

In addition, alloy steels tend to be more expensive than carbon steel options, though they are less expensive than stainless steel.

Since a lot of strength and durability comes from finishing steps applied to alloy steel, you’ll need to factor in extra time and money during the manufacturing process. You’ll also need to use a shop like Rapid Axis that offers different finishing options. 

What Is Stainless Steel?

Stainless steel is technically a form of alloy steel that contains at least 10.5% chromium by volume, which creates a thin oxide layer on the outer layer of a part, preventing corrosion for longer. In most industries, stainless steel is the more common option since it doesn’t require finishing steps to achieve corrosion resistance. 

Stainless steel is one of the more common metal options on the market. A lot of engineers we work with will use stainless as their default material, unless the project has requirements that can’t be met with stainless.

Stainless can be used to make anything from enclosures to brackets, housings, structural parts, or frames. Many major industries use stainless steel across their assemblies since it is such a versatile material that is readily available and easily sourced. 

Pros of Stainless Steel

Arguably the biggest selling point of stainless steel is its corrosion resistance. The material is also strong and durable, and the right stainless steel alloy can last a long time without any maintenance required. 

Stainless steel can be a cleanroom-compatible metal, so you can use it in semiconductor, medical, or food processing operations. 

Typically, stainless steel is easier to source and find in specific shapes. Stainless can be found in a variety of plates, sheets, rods, geometric pieces, and tubing. With a starting shape and geometry that’s closer to your final product, you can save a lot of time and money during the manufacturing operation.

Cons of Stainless Steel

Although stainless steel exceeds the performance of alloy steel in many categories, you have to pay a premium for the material; stainless steel can be a lot more expensive than standard alloy steels. 

Stainless steel can also be harder to machine, since the parts can work harden during manufacturing, which complicates machining and requires additional expertise. 

With the added cost and turnaround time for stainless steel parts, you’ll need to make sure your project has the right budget and timeline. While stainless doesn’t have the same complexity that specialty alloys have, it’s still worth mentioning since alloy steel is so much easier to machine. 

Alloy Steel vs Stainless Steel

These two categories of steel are not interchangeable. When corrosion is a risk, stainless steel is the only option unless you want to go through different finishing steps on an alloy steel part.

Alloy steel is more affordable and easier to machine, so it’s a good option for generic parts that aren’t exposed to moisture or chemicals. It’s a great choice for gears, bearings, and structural brackets.

Stainless steel tends to be more durable, a little stronger, and more long-lasting than alloy steel. Stainless is the better option for consumer goods, industrial applications, and aerospace projects. 

How to Choose Between Alloy Steel and Stainless Steel

Choosing between alloy steel and stainless steel really boils down to three factors: corrosion resistance, strength, and budget. 

Any project that requires corrosion resistance would benefit from choosing stainless steel, since it is naturally better at resisting pitting and rust.

Structural parts that require high tensile strength should use alloy steel, since their values are typically better than stainless steel’s.

For projects that need to be low-cost or mass produced while keeping your costs low, alloy steel will probably be the better option. The raw material is more affordable, manufacturing is quicker, and machining is more affordable.

Conclusion

The choice between alloy steel and stainless steel can be simple once you have enough experience with both metals. Our experts at Rapid Axis are always here to help you make the decision for the next project. With extensive experience manufacturing both alloy steel and stainless steel, you can trust our team to handle your upcoming manufacturing needs.

We offer a wide range of finishing operations under one roof, so you can get the best results, regardless of which material you choose. Reach out today to get a free quote. 

Our experts put together this quick guide to explain the differences between galvanized steel and aluminum, and help you better understand which choice is better for your next project. 

What Is Aluminum?

Aluminum is a light-weight, non-magnetic metal that is incredibly common. It’s hard to go a day in a machine shop without doing a project with aluminum, and it can be found in almost every industry from consumer products to military and aerospace applications.

Aluminum has an impressive strength-to-weight ratio, while still being very affordable and readily-available. It can be bent, welded, machined, turned, and assembled with no problems at all.

Pure aluminum is basically useless; it’s so soft that it can be damaged and deformed with very little effort. 

For that reason, it’s hard to find pure aluminum, especially in a machine shop. Instead, we (almost) exclusively use aluminum alloys, which are a combination of aluminum with other elements and materials that change the mechanical properties of aluminum.

The most common alloy is 6061, which adds magnesium, silicon, chromium, iron, zinc, manganese, and copper to make the aluminum stronger, more durable, corrosion-resistant, and longer-lasting.

Through the right combination of elements, you can find aluminum that is thermally and electrically conductive, lighter-weight, stronger, more corrosion resistant, has higher fatigue resistance, and has better formability.

Pros and Cons of Aluminum

The biggest benefit of aluminum is arguably the fact that it is so affordable, easy to work with, and has a great strength-to-weight ratio. These three reasons alone are why so many people use aluminum as their go-to metal for manufacturing projects.

With the right alloy, you can improve these properties and make aluminum parts that work perfectly in your application. This is why you’ll find aluminum used in so many major industries like aerospace, defense, robotics, electronics, and much more.

Plus, aluminum alloys are corrosion-resistant without any finishing steps, and they can be further enhanced with an anodization.

The downside is that aluminum has a worse strength-to-weight ratio than titanium and a lower overall strength value than steel, making it an “in-between” type of metal. If you need a metal to handle heavy loads, then aluminum is going to fail before steel and might not work in the first place.

What Is Galvanized Steel?

Galvanized steel is carbon steel that has gone through the galvanization process, which entails adding a thick layer of zinc to make the part corrosion-resistant. With galvanized steel, the zinc acts as a sacrificial layer that corrodes and gets damaged before the steel does. 

Since galvanized steel is so durable and strong, it is often used in construction projects and in industrial equipment. It has great corrosion-resistance and tensile strength, but it’s a lot heavier than aluminum.

Galvanized steel comes in different thicknesses and can be welded, formed, and punched with the right settings. Machining galvanized steel is harder because going through the zinc layer creates fumes that damage tooling. In most cases, we machine the part before galvanizing it.

Pros and Cons of Galvanized Steel

Galvanized steel is used for its strength and durability, especially in applications that involve heavy loads or outdoor exposure. The zinc coating lasts a long time, and it can be reapplied if it gets too damaged in the future.

Additionally, galvanized steel is more affordable than stainless steel while offering similar corrosion resistance. This strikes a nice balance between strength, cost, and performance. 

However, galvanized steel is really hard to machine and alter once the coating is applied. It requires special tools to prevent damage or contamination. Adding the coating also introduces a non-uniform thickness to parts, which makes it hard to use them in tightly-toleranced projects. To hit dimensional tolerances, we might need to do a post-processing step after fabrication.

Another issue is that steel is about three times heavier than aluminum. This makes galvanized steel a poor choice for parts that need to be lifted by hand or supported by other components that aren’t as strong.

Aluminum vs Galvanized Steel

Picking between aluminum and galvanized steel is one of the easier choices since these two materials are pretty different, with unique specialties and drawbacks. 

If your next project requires faster turnarounds and has a lower budget, then aluminum is a great choice. It’s easier and faster to machine, and the project costs tend to be less expensive. Aluminum is also the better option if you need to keep your part lightweight or it doesn’t need to handle heavy weights.

Galvanized steel is the perfect option for high-strength parts that need to support a lot of weight without corroding. When it comes to structural parts or industrial assemblies, galvanized steel is happy to do the heavy lifting, while aluminum is typically better for trim or ornamental pieces within the same industrial equipment.

In aerospace projects, it’s more rare to see galvanized steel used since lightweight parts are preferred.

Conclusion

Overall, galvanized steel and aluminum are both strong, corrosion-resistant metals that can last a really long time. With more strength available, galvanized steel is the better choice for handling heavy masses, while aluminum’s lightweight nature is good for keeping things light. 

If you’re still not sure, reach out to our team at Rapid Axis. We can look at your design and project specifications to suggest which material is best for your parts.

With extensive experience with both aluminum and galvanized steel, plus dozens of other materials, you can trust Rapid Axis for all of your prototyping or production manufacturing needs. We have the equipment, expertise, and finishing options necessary to make sure all of your parts work perfectly within your unique applications.

Get a quote today, and see how Rapid Axis can help you.