Density of Brass: g/cm³, kg/m³, lb/in³, Alloy Chart & Weight Formula

Brass is heavier than most people expect. Its density sits between 8.4 and 8.73 g/cm³—denser than steel, lighter than copper, and variable enough that the wrong number will mess up your weight estimate.

I learned this the hard way. A Tuesday afternoon in a machine shop, I grabbed what looked like a stubby aluminum rod. Same diameter, same length, totally different planet. The thing nearly yanked my shoulder out of its socket. That was the day I stopped guessing and started actually looking up the numbers.

So if you're here because you almost snapped your wrist picking up a brass fitting, or because you're about to order 50 kilos of the stuff and want to know what that actually means, you're in the right place. I'll give you the real figures, the alloy-by-alloy breakdown, and the formula you need so you never get surprised again.

Key Takeaways

• Brass density typically falls between 8.4 and 8.73 g/cm³ (or 8,400–8,730 kg/m³)
• The number shifts based on copper-to-zinc ratio: more copper = heavier, more zinc = lighter
• C26000 cartridge brass lands around 8.53 g/cm³—a reliable mid-range reference
• Temperature, cold working, and trace elements like lead or tin all nudge the density up or down
• You can estimate brass weight with a simple formula: Weight = Volume × Density 

Why There's No Single "The Density of Brass" Answer

Here's the thing that trips people up right from the start. Brass is not one material.

Steel is basically iron plus a little carbon. The variation is small. Brass, though, is a copper-zinc alloy where the ratio changes depending on what the alloy is designed to do. Change the ratio, change the density. It really is that direct.

Pure copper sits at about 8.96 g/cm³. Pure zinc is around 7.14 g/cm³. Brass lives somewhere in between, pulled toward one side depending on which component dominates. Add tin for corrosion resistance? Slight shift. Add lead for machinability? Another shift. It all compounds.

Variable	Effect on Density
More copper (toward 90%)	Pushes density higher (closer to 8.75 g/cm³)
More zinc (toward 40%)	Pulls density lower (toward 8.4 g/cm³)
Added lead (~3%)	Slight decrease due to microstructure disruption
Added tin (~1%)	Minor increase; improves corrosion resistance
Cold working	Slight increase (grain compaction)
Temperature rise (+100°C)	Roughly 1.5–2% decrease

So when someone on a forum says "brass density is 8.5," they're not wrong. They're just giving you a working average. For general estimates? That's fine. For precision engineering, material ordering, or quality control? You need the specific alloy.

The Full Brass Alloy Density Chart (By Grade)

I keep a printed version of this taped above my desk. Not because I can't Google it, but because I kept Googling it five times a week and eventually figured I should just make it permanent.

The grades below are the ones you'll actually encounter in a machine shop, a plumbing supply house, or an engineering spec sheet.

Alloy (UNS)	Common Name	Density (g/cm³)	Density (kg/m³)	Density (lb/in³)
C26000	Cartridge Brass	8.53	8,530	0.308
C27000	Yellow Brass	8.47	8,470	0.306
C36000	Free-Cutting Brass	8.50	8,500	0.307
C46400	Naval Brass	8.41	8,410	0.304
C83600	Red Brass (Leaded)	8.75	8,750	0.316
C26800	Yellow Brass (Low Zn)	8.47	8,470	0.306

Notice the spread. Red brass (C83600) at 8.75 g/cm³ is nearly 4% denser than naval brass (C46400) at 8.41 g/cm³. That might sound small, but across 500 kg of material? You're looking at a 20 kg discrepancy. That's a real shipping cost difference.

Here's a side-by-side comparison of the big three workhorse grades:

Grade	Cu %	Zn %	Other	Key Use
C36000 (Free-Cutting)	~61.5%	~35.5%	~3% Pb	CNC machining, fittings
C26000 (Cartridge)	~70%	~30%	—	Ammunition casings, cold-forming
C46400 (Naval)	~60%	~39.25%	~0.75% Sn	Marine hardware, propeller shafts

The lead in C36000 is worth noting. Lead itself is pretty dense (around 11.3 g/cm³), which makes you think it'd push the overall density up. But at just 3% addition, what it actually does is disrupt the crystal lattice. The net result is a slightly lower apparent density compared to unladed brass of similar copper content. Materials science loves to be counterintuitive like that.

Brass Density vs. Other Common Metals

You're probably wondering where brass sits on the broader spectrum. Let me just show you.

Metal	Density (g/cm³)	Compared to Brass
Aluminum	2.70	~3× lighter
Titanium	4.51	About half of the brass
Zinc	7.14	Noticeably lighter
Steel (carbon)	7.85	~8% lighter
Stainless Steel	7.98	Slightly lighter
Brass (average)	8.4–8.73	—
Bronze	8.7–8.9	Very close, slightly heavier
Copper	8.96	~5% heavier than brass
Silver	10.49	Significantly heavier
Gold	19.32	Not even the same universe

Am I wrong, or does it surprise people that brass is heavier than steel? I've had that conversation more than once. Someone assumes brass is the lighter, decorative metal and steel is the serious heavy one. Nope. For the same volume, a brass part weighs roughly 8–10% more than an equivalent carbon steel part. That matters a lot in weight-reduction design work.

The bronze comparison is also worth paying attention to. Bronze typically runs 8.7–8.9 g/cm³, which overlaps the high end of brass's range. If you're trying to distinguish brass from bronze without testing, density alone won't always save you. Color is usually more reliable—brass runs yellow-gold, bronze runs more reddish-brown.

How to Actually Calculate Brass Weight (The Formula You Need)

This is the practical part. Stop reading specs and start computing.

The formula is simple:

$$\text{Weight} = \text{Volume} \times \text{Density}$$

Where volume is in cm³ and density is in g/cm³, the output is grams. Divide by 1,000 for kilograms.

Example 1: Brass bar (solid rod)

A brass rod, 2 cm diameter × 50 cm long.

Volume of cylinder = π × r² × h = 3.14159 × 1² × 50 = 157.08 cm³

At C36000 density of 8.50 g/cm³:

Weight = 157.08 × 8.50 = 1,335 g ≈ 1.34 kg

Example 2: Brass sheet

Sheet that's 0.3 cm thick × 60 cm × 100 cm.

Volume = 0.3 × 60 × 100 = 1,800 cm³

At 8.47 g/cm³ (yellow brass):

Weight = 1,800 × 8.47 = 15,246 g ≈ 15.25 kg

Shape	Volume Formula	Notes
Solid rod/bar	π × r² × length	Use radius, not diameter
Rectangular bar/sheet	L × W × thickness	All in same unit
Hollow tube	π × (R² − r²) × length	R = outer radius, r = inner
Hex bar	(3√3/2) × s² × length	s = side length

For more complex shapes—especially irregular castings—use water displacement to find volume (more on that in a moment), then plug it into the same formula. A metal weight estimator tool handles all of this automatically if you're doing repetitive calculations for quotes or material orders; worth having bookmarked.

One thing beginners miss: always add 2–5% for cutting waste when ordering bar stock. You calculate you need 10 kg? Order 10.5 kg. Watched a whole project get delayed once because someone forgot this step and ran short mid-run.

What Actually Changes Brass Density in the Real World

Manufacturing Method

Cast brass and wrought brass behave differently. During casting, molten brass shrinks as it solidifies and can trap tiny air pockets inside. The actual density of a casting can run about 1.5% lower than the published theoretical value.

Wrought brass—rolled, drawn, or extruded—is more compact. Cold drawing in particular tightens the grain structure, pushing density closer to the theoretical maximum. If you're doing precise mass calculations for a machined component vs. a casting, these aren't the same number. Account for it.

Production Method	Effect on Density	Notes
Investment casting	~1–1.5% below spec	Porosity, shrinkage voids
Sand casting	~1–2% below spec	Coarser grain, more voids
Hot rolling	Near spec	Good density, slight grain elongation
Cold drawing	At or slightly above spec	Grain compaction
Forging	Near spec, high uniformity	Minimizes internal flaws

Temperature

This one matters more than most people think. Heat any solid and it expands. Expand the volume, drop the density.

For brass, the relationship is roughly linear. Tests show a drop of about 0.5% in density per 100°C increase. Heating to 100°C reduces density by around 1.5–2%. That means:

• At 20°C: ~8.50 g/cm³
• At 100°C: ~8.35–8.38 g/cm³
• At 200°C: ~8.25–8.30 g/cm³

For most workshop applications, you can ignore this. But if you're designing valves, fluid fittings, or any component that operates at elevated temperatures, those tolerances shift. Pressure simulations run at room temperature won't match real-world performance at 150°C. That's not a small detail—it's a systematic error in your model.

Impurities and Recycled Material

Here's one nobody talks about openly. Some suppliers blend scrap into their brass. If the recycled material contains off-spec aluminum (density ~2.7 g/cm³) or excess iron, your actual density drops below the published figure.

A measured density noticeably below 8.4 g/cm³ on what's supposed to be standard brass? That's a red flag. Always request a Material Test Report (MTR) from suppliers for anything going into a precision application, and cross-reference the chemistry against expected density. A deviation of 0.1 g/cm³ from 8.5 g/cm³ can indicate a zinc content imbalance of roughly 5–7%, which directly affects corrosion resistance and mechanical strength.

How to Measure Brass Density Yourself (Three Methods)

You picked up a piece of mystery brass. No markings. You want to know what you've actually got. Here's how.

Method 1: Archimedes Principle (Best for Irregular Shapes)

This is the water displacement method. Old, reliable, needs nothing fancy.

1. Weigh the brass piece in air. Record mass (g).
2. Fill a container with water. Lower the brass piece in on a string. Record the apparent weight while submerged.
3. The difference = weight of displaced water = volume of the brass piece (since 1 g of water = 1 cm³).
4. Density = Mass in air ÷ Volume

Formula shorthand:
$$\rho = \frac{W_{air}}{W_{air} - W_{water}}$$

Example: A piece weighs 500 g in air and 442 g underwater. Volume = 500 − 442 = 58 cm³. Density = 500 ÷ 58 = 8.62 g/cm³. That's solidly in the red brass range.

Method 2: Dimension-Based Calculation (Regular Shapes)

For bars, rods, sheets, and tubes with clean geometry:

1. Measure dimensions precisely with calipers
2. Calculate volume from the appropriate geometric formula
3. Weigh on a scale
4. Density = Mass ÷ Volume

Tool Needed	Precision Level	Best For
Ruler + kitchen scale	Low (~±3%)	Quick rough checks
Digital calipers + lab scale	Medium (~±0.5%)	Workshop verification
Precision balance + density kit	High (~±0.01%)	QC and engineering

Method 3: Density Meter (Industrial Standard)

Dedicated density measurement devices use buoyancy and electronic force measurement to compute density automatically. Accurate to ±0.0001 g/cm³. If you're running incoming material checks on a production line, this is the tool to use. Automated density checks can reduce defect rates by 18–22% in precision machining, according to some manufacturing studies.

Brass Density by Application: Why the Alloy Choice Matters

I grabbed a copy of Copper and Copper Alloys from ASM International off my shelf while writing this. It's dry as sandpaper, but it lays out exactly why certain alloy densities matter for specific end uses. Worth having if you work with non-ferrous metals seriously.

The density of the brass you pick directly affects three things: structural load, shipping weight, and material cost (since most brass is priced by weight).

Application	Recommended Alloy	Density (g/cm³)	Why This Density
Marine fittings/propeller shafts	C46400 Naval Brass	8.41	Lighter for load balance; tin adds corrosion resistance
Plumbing valves/pipe fittings	C83600 Red Brass	8.75	High copper for dezincification resistance in water
CNC-machined parts	C36000 Free-Cutting	8.50	Stable, predictable mass for tolerancing
Ammunition casings	C26000 Cartridge	8.53	Higher ductility; consistent density for uniform forming
Musical instruments	Various (high Cu)	8.5–8.7	Density affects acoustic resonance, and weight feels
Decorative architectural	C27000 Yellow Brass	8.47	Lighter for facade cladding; easier to form

Musical instruments are a fun case. The density of brass in a trumpet bell isn't just about weight—it influences acoustic properties, specifically how the metal resonates. Higher-density alloys tend to produce a brighter, more projecting tone. Brass players sometimes specifically request certain alloy specs from instrument makers for this reason. A dense alloy is doing work in two different industries for completely different reasons.

Electrical and electronic applications lean on brass for conductivity combined with machinability. Dense brass connectors, terminals, and switch components hold tight tolerances better than lighter alternatives. In high-frequency environments, the mass of dense brass helps reduce energy loss through vibration damping. That's a non-obvious use of a physical property.

The SI and Imperial Unit Conversions (Full Chart)

Because brass density shows up in three different unit systems depending on who you're talking to.

Unit System	Value	Unit
SI (metric)	8,530	kg/m³
CGS	8.53	g/cm³
SI (per liter)	8.53	kg/L
SI (per mL)	8.53	g/mL
Imperial	0.308	lb/in³
Imperial	532.8	lb/ft³
Imperial	14,387	lb/yd³
Avoirdupois	4.97	oz/in³

The one that catches people off guard most often is lb/in³. American machinists often work in this unit, and 0.308 lb/in³ for standard cartridge brass is the number to memorize if you're quoting weight-based pricing or doing weight-per-volume specs on a drawing.

A quick conversion reference:

$$\text{g/cm}^3 \times 1000 = \text{kg/m}^3$$ $$\text{g/cm}^3 \times 0.0361 = \text{lb/in}^3$$ $$\text{kg/m}^3 \times 0.0624 = \text{lb/ft}^3$$

Detecting Substandard Brass by Density (Quality Control)

Here's a practical use of everything above that not enough people actually do.

Say you receive a batch of C26000 cartridge brass. The spec says 8.53 g/cm³. You spot-check a piece with the Archimedes method and get 8.28 g/cm³. That's a red flag.

What does a 0.25 g/cm³ drop tell you?

• Likely higher zinc content than specified (zinc being ~7.14 g/cm³ will pull the average down)
• Possible contamination with aluminum or other lighter metals from recycled scrap
• Potential internal porosity from poor casting control

Any of these will affect performance. Higher zinc increases susceptibility to dezincification—a form of corrosion that selectively leaches zinc from the alloy, leaving a porous copper-rich structure that looks solid but crumbles under load. Not what you want in a valve body or hydraulic fitting.

Measured Density vs. Spec	Likely Cause	Risk
Within ±0.05 g/cm³	Normal variation	Low
0.05–0.15 g/cm³ below spec	Slightly high zinc or minor impurities	Moderate—test further
0.15+ g/cm³ below spec	Significant alloy deviation or contamination	High—reject lot
Above spec by 0.1+ g/cm³	Excess lead or copper-rich blend	Test composition

Standards like ASTM B36 (brass plate, sheet, strip, and rolled bar) set density-linked composition tolerances for exactly this reason. Non-destructive ultrasonic density checking can catch deviations early in production, before a defective lot makes it to final machining.

FAQ

What is the density of brass in g/cm³?

Standard brass density falls between 8.4 and 8.73 g/cm³. For a single working number, use 8.5 g/cm³. For specific grades: C26000 cartridge brass is 8.53 g/cm³, C46400 naval brass is 8.41 g/cm³, and red brass (C83600) sits around 8.75 g/cm³.

Is brass denser than steel?

Yes. Most carbon steel runs around 7.85 g/cm³. Standard brass at 8.5 g/cm³ is roughly 8% heavier by volume. Stainless steel (about 7.98 g/cm³) is also lighter than brass. This surprises a lot of people.

Is brass more or less dense than copper?

Less. Pure copper is about 8.96 g/cm³. Brass contains zinc (7.14 g/cm³), which brings the overall density down. The more zinc in the alloy, the lighter the brass.

Does brass density change with temperature?

Yes. Brass expands when heated, lowering its density. The drop is approximately 0.5% per 100°C increase. Heating from 20°C to 100°C reduces density by roughly 1.5–2%. For room-temperature applications, ignore this. For high-temp valve or fitting design, factor it in.

What is the density of brass in kg/m³?

Convert g/cm³ to kg/m³ by multiplying by 1,000. Standard brass: 8,500 kg/m³. Cartridge brass C26000: 8,530 kg/m³. Naval brass C46400: 8,410 kg/m³.

How do I measure brass density without special equipment?

Use Archimedes' principle. Weigh the piece in air, then weigh it again while submerged in water. Density = Weight in air ÷ (Weight in air − Weight in water). For regular shapes, you can measure dimensions with a ruler, calculate volume geometrically, weigh on a scale, and divide mass by volume.

What is the density of brass in lb/in³?

Cartridge brass C26000: 0.308 lb/in³. Naval brass C46400: 0.304 lb/in³. Free-cutting brass C36000: 0.307 lb/in³. Red brass C83600: approximately 0.316 lb/in³.

Why do brasses have different density values in different sources?

Because brass is not one alloy—it's a family of copper-zinc alloys with varying compositions. Each grade has its own density. Sources citing 8.4, 8.5, 8.6, or 8.73 g/cm³ are all correct for different grades. Always match the density value to the specific alloy, not just "brass" generically.

Can I use brass density to check material quality?

Yes. A measured density significantly below spec (more than 0.15 g/cm³) suggests off-spec zinc content, impurities, or casting porosity. Request a Material Test Report and compare the chemistry to the expected range. This is standard practice in quality control for precision components.

How does brass density compare to bronze?

Bronze typically runs 8.7–8.9 g/cm³, slightly higher than most brass alloys. If you're trying to distinguish them by density alone, the overlap makes it tricky—especially with high-copper red brass sitting near the bronze range. Composition testing or color evaluation is more reliable for definitive identification.

The density of brass is one of those things that seems simple until you actually need to use it. It's not one number. It's a range tied to alloy, process, and temperature. But now you have the whole picture—the grades, the formulas, the measurement methods, and the quality flags. Next time you pick up a brass rod, you'll at least know what you're lifting.