Brass, which is mostly copper and zinc, is popular because it’s easy to shape, doesn’t rust easily, and looks good. How heavy it is matters a lot when using it for precise parts, especially in fields where things need to be just right. Knowing its density helps engineers and makers pick the best stuff for certain uses, so things work well and last a long time.
What Is Brass? Composition and Key Properties
In short, brass is a mix of copper and zinc. Unlike gold or silver, it’s not a single element but a non-ferrous alloy that can be tweaked to get certain properties.
Usually, brass has 60% to 90% copper, with zinc making up the rest. To make it easier to cut or more resistant to rust, factories might add a bit of lead or tin. Because of slight changes in these recipes, brass metal density isn’t a set number. It changes based on what the alloy is made of.
What Is the Exact Density of Brass?
If you’re looking for a quick engineering reference, the usual figure for brass density is 8.5 g/cm³. But if you’re doing really exact physics simulations or weight calculations, that general number might not cut it.
Here are the key figures to keep in mind for different measuring systems:
- Brass density in kg/m³: Usually falls between 8,400 and 8,730 kg/m³.
- Brass weight per cubic inch: Roughly 0.303 to 0.315 lb/in³.
When someone asks you, what is the density of brass? the best answer is: It depends on how much zinc is in it. Zinc’s density (around 7,140 kg/m³) is much lower than copper’s (about 8,960 kg/m³), so for every 1% increase in zinc, the brass’s density goes down a bit.
C360 vs. C260 Density: A Detailed Alloy Grade Chart
When you’re knee-deep in CNC machining and mechanical design, you’ll usually run into these specific material grades. Forget about vague averages—let’s look at some real numbers:
C360 (Free Cutting Brass)
It usually has a density around 8.50 g/cm³ (0.307 lb/in³). It’s a common sight in North American machine shops because it has about 3% lead added. Since lead is pretty dense, it balances out the weight reduction from the zinc. This makes C360 feel solid and perform consistently.
C260 (Cartridge Brass)
It usually has a density around 8.53 g/cm³ (0.308 lb/in³). With a higher copper content (around 70%), it’s a bit denser than C360. This small difference matters when you’re making millions of cartridge cases or cold-formed parts, as it impacts how much raw material you need to buy.
C464 (Naval Brass)
It usually has a density around 8.41 g/cm³ (0.304 lb/in³). It trades off some density for better corrosion resistance against seawater. If you’re making parts for ships, don’t just use C360’s values, or your weight estimates will be off by about 1%.
| Alloy Grade (UNS) | Density (g/cm3) | Density (kg/m3) | Density (lb/in3) | Main Characteristics |
| C36000 (Free Cutting) | 8.50 | 8,500 | 0.307 | High lead content, stable mass, industry standard for CNC. |
| C26000 (Cartridge) | 8.53 | 8,530 | 0.308 | Higher copper ratio, slightly heavier, superior ductility. |
| C46400 (Naval Brass) | 8.41 | 8,410 | 0.304 | Tin addition for corrosion resistance, lowest density in this group. |
Why Your Weight Calculations Are Wrong: 3 Manufacturing Factors
Even if you pick the right material, the actual weight can still surprise you. Usually, it’s not the calculator’s fault but that you’re ignoring some physics in industrial making.
Casting Pores
If you’re dealing with cast brass, the real density is often around 1.5% lower than the stated brass metal density. That’s because the melted metal forms tiny air pockets or shrinks as it cools. When figuring out the cost of big castings, skipping this air can make your raw materials seem pricier than they are.
How It’s Made and Heat Treating
Cold drawing and hot rolling have a slight impact on density. These shouldn’t be ignored in precision work. Cold drawing makes the crystal structure tighter, getting rid of some tiny gaps, which makes the density closer to the theoretical maximum. For aerospace parts, even these small differences in mass can mess with dynamic balancing tests.
Impurity Control and Recycled Material
Here’s one of the trade’s biggest secrets. To cut costs, some suppliers mix in scrap. If the alloy has too much aluminum (density about 2.7 g/cm³) or iron, the final brass density will be much lower. If the density you measure is way off from the standard range, that’s a sign that the material might not be pure.
Temperature & Density: How Heat Affects Brass Mass Density
In the physical world, things usually expand when heated and shrink when cooled. When brass gets hot, it expands, and its density decreases.
This change follows a linear pattern. Tests show that brass density drops by about 0.5% for every 100°C increase. Ignoring this in tasks like mold design or when using high-temperature fluid valves can cause issues with precision parts shifting during operation.
- Normal room temperature (20°C): About 8.50 g/cm^3
- High temperature (200°C): About 8.42 g/cm^3
When figuring out fluid flow rates or dynamic loads in high-temperature setups, you need to factor in this compensation. If you don’t, your pressure simulation data will be wrong from the start.
How to Calculate Brass Weight: Formulas for Bars, Sheets & Tubes
Stop just throwing parts on the scale. Learn these formulas to control your budget before ordering.
Round and Hex Bars
For common bar stock, use this quick conversion:
Weight (kg) = Cross-sectional area (mm²) × Length (m) × Density Factor
For standard brass, the density factor is usually 0.0085.
Tip: Add 2%-5% for cutting waste. Beginners often miss this cost.
Brass Sheets and Strips
Weight (kg) = Thickness (mm) × Width (m) × Length (m) × 8.5
When working with large decorative brass sheets, thickness tolerance matters. Even if a supplier’s sheet is just 0.05mm thicker, the added weight and shipping for 100 square meters can cost you.
Calibration in CAD Modeling
In SolidWorks or AutoCAD, don’t select the generic Brass property. Go into the material library and manually enter the mass density of the exact grade you bought (like C360). This way, the mass property report will support your structural analysis.
In precision CNC brass part machining, accurate quality attribute settings not only affect weight but also directly determine the dynamic balance performance of high-speed rotating components.
Is brass more dense than copper?
No, pure copper is heavier than brass. Copper’s density is about 8.96 g/cm³, but brass includes lighter zinc (7.14 g/cm³), which lowers its density to around 8.5 g/cm³. If you can’t tell the metals apart by looking at them, weighing them is a helpful way to tell which is which.
While density is one way to distinguish materials, the difference between brass and bronze is more pronounced in terms of corrosion resistance. You can read our in-depth comparison guide to select the material best suited for marine environments.
Is brass heavier than steel?
Yes. This is a common misconception. In fact, brass is heavier than most carbon steels. Carbon steel has a density of approximately 7.85 g/cm³, meaning that for the same volume, brass parts weigh about 8% more than steel parts. This difference must be taken into account when designing weight-reduction structures or calculating logistics loading.
How can I detect brass quality by its density?
Use Archimedes’ principle of water displacement. First, weigh the item in the air. Then, weigh it fully underwater. Then, calculate the actual density using this formula:
Density = Weight in Air / (Weight in Air – Weight in Water).
If the result is much lower than 8.4 g/cm³, the material in your hand probably has cheap metals like aluminum mixed in, or it has major casting flaws inside.
Avoiding Pitfalls in the Industry: How to Identify “Fake” Brass Parameters
In global trade, a few suppliers might use average figures to hide when materials are below standard.
Say you’re buying high-grade C260 cartridge brass, but the supplier’s density measurements are around 8.4 g/cm³. That likely means too much zinc or other junk is mixed in. This density difference can cause cracks later on when you heat-treat or stamp the material.
Always ask your suppliers for Material Test Reports (MTRs). Then, check if the chemistry on the report matches the expected density of brass.
Conclusion
Picking the right brass density isn’t just about numbers; it really impacts how well your product works and how much money your business makes. Each type, like the strong C360 or the lighter C464, has its own special traits.
Before you order next time, check out the chart in this article and tweak the numbers based on how you’re making things, whether it’s casting or forging.
At Baosheng, we’ve been in the precision manufacturing game for a while, so we understand that even the tiniest detail matters. We don’t just sell top-notch brass that meets ASTM standards. We also use our decades of experience to give you precise material reports and advice. This way, you know your quotes and designs are spot-on.
Ready to make your projects better? Get in touch with Baosheng’s tech team now for a brass density chart made just for you, or to find the best material for your next tricky part.
