Is Copper Heavier Than Brass? Density Compared With Real Numbers

Copper is heavier than brass. At the same volume, pure copper weighs about 8.96 grams per cubic centimeter. Brass runs 8.4 to 8.73 grams per cubic centimeter, depending on how much zinc is mixed in. That puts copper roughly 3-6% heavier than brass for an identical size and shape.

The gap sounds small, and by weight percentage it is. But it's consistent, it's measurable, and it matters the moment you're specifying milling materials for a part where weight is part of the design, not just an afterthought.

TL;DR / Key Takeaways

• Copper density: about 8.96 g/cm3 (8,960 kg/m3, 0.324 lb/in3)
• Brass density: 8.4-8.73 g/cm3 depending on zinc content, with common alloys like C26000 cartridge brass sitting around 8.53 g/cm3
• Copper is about 3-6% heavier than brass for the same volume
• Weight always depends on volume, not density alone - a larger brass part can still outweigh a smaller copper one
• Both metals are machined through Haizol's verified CNC factories in China and sheet metal fabrication network, so the weight difference is a real spec consideration, not just trivia

 

Is Copper Heavier Than Brass?

Copper is heavier than brass, gram for gram, at the same volume. This comes down to atomic structure, not manufacturing or alloy quality: copper is a single element with a tightly packed crystal lattice, while brass is copper alloyed with zinc, an element that's less dense than copper on its own.

The actual figures are well documented, and they hold regardless of which specific brass alloy you're comparing against, since even the lightest common brass alloys don't drop below roughly 8.4 g/cm3.

The one thing this simple yes/no answer leaves out is volume. Two objects of different sizes don't follow this rule automatically - more on that in the section on brass parts that outweigh copper ones.

What Is the Density of Copper and Brass?

Copper has a density of about 8.96 g/cm3. Brass ranges from 8.4 to 8.73 g/cm3, with the exact number depending on how much zinc is in the specific alloy.

Brass is copper alloyed with zinc, typically in a 60-90% copper to 10-40% zinc ratio depending on the grade, according to the Copper Development Association's alloy composition data. Adding zinc, which has a lower density than copper, is exactly why brass consistently comes in lighter than pure copper, no matter which specific alloy you're using.

Copper and brass are not the same metal, even though they're closely related and often mistaken for each other on sight. Copper is a pure element. Brass is an alloy, meaning its density, color, and mechanical properties all shift depending on the zinc percentage a given supplier used - which is also why you'll see a range for brass density instead of one fixed number, while copper's density figure stays essentially constant.

Material	g/cm3	kg/m3	lb/in3
Copper (pure, C11000)	8.96	8,960	0.324
Brass, general range	8.4-8.73	8,400-8,730	0.303-0.315
Brass C26000 (cartridge brass, ~30% zinc)	8.53	8,530	0.308
Brass C36000 (free-cutting brass)	8.50	8,500	0.307

The 8.96 g/cm3 figure for copper is the standard pure-copper reference value used across general engineering literature. The Copper Development Association's own C11000 alloy datasheet lists a slightly lower measured specific gravity of 8.91 (0.322 lb/in3) for commercial electrolytic tough pitch copper, a roughly 0.5% difference from trace impurities that doesn't change any conclusion in this guide.

The C26000 cartridge brass figure of 8.53 g/cm3 comes directly from that same Copper Development Association alloy database, the industry reference for wrought copper and copper alloy properties.

Sidenote. Density varies by alloy grade because zinc content varies. Higher-zinc brasses (up to 40% zinc) sit closer to the bottom of that 8.4-8.73 g/cm3 range; lower-zinc, higher-copper brasses like C21000 gilding metal (95% copper) sit closer to the top, nearer copper's own density.

How Much Heavier Is Copper Than Brass?

Copper is about 3-6% heavier than brass for the same volume, depending on which brass alloy you're comparing against. Against a mid-range brass alloy like C26000 (8.53 g/cm3), copper's 8.96 g/cm3 works out to roughly 5% heavier.

That 3-6% range isn't sloppy rounding - it reflects the real spread in brass density across common alloys, not measurement uncertainty. Compare copper against a lower-zinc, higher-density brass and the gap shrinks toward 3%. Compare it against a higher-zinc, lower-density brass and the gap opens toward 6%.

For most day-to-day estimating purposes, treating copper as roughly 5% heavier than brass by volume is a reasonable working number. If you need a precise figure for a specific part, use the exact density of the specific brass alloy you're specifying, not the general range.

Can a Brass Part Still Weigh More Than a Copper Part?

Brass part can weigh more than a copper part, even though brass is the less dense material. Weight depends on density multiplied by volume, and volume is the variable that everyone forgets.

Here's a concrete example. A 10 cubic centimeter block of copper weighs about 89.6 grams. A 10 cubic centimeter block of brass (using the 8.53 g/cm3 mid-range figure) weighs about 85.3 grams - lighter, as expected.

But double the brass block to 20 cubic centimeters and it weighs about 170.6 grams, nearly twice the weight of the smaller copper block, despite brass being the "lighter" material by density.

This isn't a trick of the numbers. It's the same logic that makes a large plastic crate heavier than a small steel bolt. Density tells you which material is denser at equal volume.

It tells you nothing about which specific part, of whatever actual size someone hands you, weighs more. If you're comparing two parts and one is noticeably bigger, don't assume the material with the lower density automatically means the lighter part.

What Do Copper and Brass Weigh in Real Parts and Fittings?

A same-size copper part will consistently outweigh its brass equivalent by roughly 3-6%, which becomes a real, specifiable number once you're looking at an actual part geometry instead of an abstract block.

Take a small CNC-machined bushing: 25 millimeters outer diameter, 20 millimeters inner diameter, 30 millimeters long. That geometry works out to about 5.3 cubic centimeters of material.

In copper, that bushing weighs approximately 47.5 grams. In brass (C26000), the same bushing weighs approximately 45.2 grams - a difference of about 2.3 grams, or roughly 5%.

Part Example	Volume	Copper Weight	Brass Weight (C26000)	Difference
Small bushing (25mm OD x 20mm ID x 30mm long)	~5.3 cm3	~47.5 g	~45.2 g	~2.3 g (5%)
10 cm3 reference block	10 cm3	89.6 g	85.3 g	4.3 g (5%)
1 cubic inch reference block	16.4 cm3	146.9 g (0.324 lb)	139.9 g (0.308 lb)	7.0 g (5%)

At small part sizes, a few grams rarely changes a sourcing decision on its own. Scale that same 5% difference across a production run of several thousand parts, and it starts showing up in shipping weight and per-unit material cost, which is exactly where this stops being trivia and starts being a specification question.

Why Does Weight Matter When Choosing Between Copper and Brass for Manufacturing?

Weight matters when choosing between copper and brass because it affects shipping cost at volume, functional performance in weight-sensitive assemblies, and how the two materials trade off against machinability and corrosion resistance.

For most fittings, connectors, and decorative hardware, the 3-6% weight difference is not the deciding factor - machinability, cost, and corrosion resistance usually matter more. Brass, especially free-cutting grades like C36000, machines faster and produces cleaner cuts than pure copper, which carries a machinability rating of only about 20% against free-cutting brass's 100% benchmark and tends to be gummy and load up cutting tools. That's often a bigger factor in the final part cost than the small density gap.

Corrosion resistance follows a similar pattern of small print that matters more than it looks. Both metals resist corrosion well in normal conditions, but brass generally holds up better in marine and high-moisture environments, while copper's own oxide layer is what gives it that long-term antimicrobial and conductive advantage in plumbing and electrical work. Neither advantage has anything to do with which one is heavier - they're separate specification decisions that happen to involve the same two metals.

Weight becomes the deciding factor in a narrower set of cases: aerospace and automotive components where every gram is tracked against a weight budget, or the opposite case, counterweights and flywheel components where mass itself is the design requirement and copper's extra density is the whole point of specifying it.

Frequently Asked Questions About Copper and Brass Weight

The density and weight numbers above answer the core question, but a few related questions come up just as often when buyers or hobbyists are comparing copper and brass. Here's the direct answer to each.

What Is Brass Made Of?

Brass is made of copper alloyed with zinc, typically 60-90% copper and 10-40% zinc depending on the grade. Higher-zinc brasses trend toward the bottom of brass's 8.4-8.73 g/cm3 density range, since zinc is less dense than copper.

Is Brass Heavier Than Copper?

No, brass is not heavier than copper at the same volume. Brass's zinc content brings its density down to 8.4-8.73 g/cm3, compared to copper's roughly 8.96 g/cm3, which is why copper consistently comes out 3-6% heavier gram for gram.

How Can You Tell Copper and Brass Apart?

Copper and brass are easiest to tell apart by color: copper has a reddish-orange tone, while brass looks more yellow-gold because of its zinc content. Neither metal is magnetic, so a magnet test won't distinguish them from each other, though it will rule out steel or iron parts mixed into a scrap pile.

Is Bronze Stronger Than Brass?

Bronze is a separate copper alloy made with tin instead of zinc, and it's generally harder and more wear-resistant than brass, though the exact comparison depends on the specific alloy grades involved. Bronze and brass are distinct alloys from each other and from copper, and the weight comparison in this guide applies specifically to copper and brass, not bronze.

Copper's Extra Density Is Small, but It's Real

Copper is heavier than brass, and the number behind that answer is consistent: copper's roughly 8.96 g/cm3 density runs about 3-6% higher than brass's 8.4-8.73 g/cm3 range, depending on the specific alloy. That difference holds at any given volume, whether you're comparing raw blocks, cubic inches, or a machined bushing off the production line.

What changes the answer isn't the material, it's the size of the part you're actually holding. A large brass component can weigh more than a small copper one, because total weight is density multiplied by volume, not density alone.

So is copper heavier than brass? Yes, at equal volume, by a small but real and specifiable margin - just don't assume that settles which of two differently-sized parts weighs more.