Humans have been producing and using brass, one of the oldest alloys, for millennia. Its workability, hardness, corrosion resistance, and attractive appearance made it a staple of ancient metallurgy for both practical and decorative purposes. Brass is such a versatile material that it is still used for many engineering and manufacturing applications today.
Humans have been using aluminum for a much shorter time than brass, but its incredible properties, especially its strength-to-weight ratio, have made it one of the most commonly used metals in the world.
In terms of machining, brass and aluminum both perform well. Even though brass has existed for much longer than modern machining processes, its mechanical properties make it perfect for machining, even in home shops that may not have expensive industrial equipment.
In this post, we’ll look at some of the characteristics of brass that make it a great choice for machining, then we’ll go over some guidelines for machining brass vs. aluminum.
What is Brass?
Brass is a generic name for a range of copper-zinc alloys that have been produced for thousands of years. Isolated examples appear in the archaeological record as early as the 5th millennium B.C., though the difference between brass and bronze was not fully understood until the medieval period. Contrasted with aluminum, which was not produced industrially until the late nineteenth century, brass has had a much longer role in human history.
Different alloys of brass can be produced by changing the proportion of zinc or adding other elements like lead or tin. Some common brass alloys include:
- Free-machining brass (C360): The most common brass alloy for machining. The addition of lead improves its machinability.
- Naval brass: Contains tin to suppress zinc leaching in marine environments.
- Rivet brass: A cheap brass alloy containing more copper used for fasteners and standard cold working applications.
In addition to decorative objects, the low friction and excellent corrosion resistance of brass make it suitable for fluid-handling components like valves and hoses. Also, its malleability and acoustic characteristics make it a traditional material for musical instruments.
Machining Brass vs. Aluminum
Brass is one of the easiest materials to machine, even compared to aluminum. Free-machining brass in particular is specifically alloyed to withstand high-speed milling with minimal wear on tooling while producing easily cleared chips.
The superior machinability of free-machining brass is the result of the addition of lead to the alloy. Lead is softer than copper and zinc, and it has a lower coefficient of friction, so it acts as a lubricant. This allows it to be cut at lower power and higher speeds while causing very little tool wear.
If you’re used to working with aluminum, brass should give you few problems. Machining brass vs. aluminum is just a matter of accounting for brass’s slightly higher hardness. In fact, machining brass is a lot like machining harder aluminum alloys like 7075. You can machine brass using the same recipes as 6061 aluminum, dialed back by around 15 percent.
The inclusion of lead can be a concern for some applications, so free-machining brass isn’t the best option for every application. Unleaded brass is still readily machinable, but it’s harder than free-machining brass and generates more friction and heat when machining. It takes longer to machine unleaded brass, and not every tool or machine that can cut free-machining brass can cut unleaded brass.
Your Local Source for Brass for Any Project
If you’re looking at the advantages of machining brass vs. aluminum for your next project, Industrial Metal Service is here to help. For more than two decades, we’ve been providing metal recycling services to the San Francisco Bay Area as well as supplying local machine shops, fabricators, and metalworkers with metals like brass and aluminum. We also ship to customers across the U.S. who don’t have the benefit of a local supplier—with no minimum order quantities.
We stock an extensive inventory of brass alloys and offer customers the option of buying new metal sourced from U.S. mills or verified remnants, which offer considerable savings.