Brass Alloy Grades Explained: C36000 vs C26000 vs C46400 — Which Grade Do You Need?

Choosing the right brass alloy grade is one of the most important decisions in component manufacturing. The grade determines how easily the material can be machined, how well it resists corrosion, how strong the finished part will be, and ultimately how long it will last in service.

Yet many engineers and procurement professionals rely on generic "brass" specifications without understanding the significant performance differences between grades. A part machined from C36000 will perform very differently from one made of C26000 or C46400 — even though all three are technically brass. This guide breaks down every major brass grade so you can make an informed material selection.

1. What Are Brass Alloy Grades?

Brass alloy grades are standardized classifications that define the exact chemical composition and resulting properties of a brass alloy. Every grade specifies the percentage of copper, zinc, and any additional alloying elements (lead, tin, aluminum, silicon, nickel) present in the material.

These grades exist because even small changes in composition create measurable differences in machinability, strength, ductility, corrosion resistance, and electrical conductivity. A 5% shift in zinc content, or the addition of just 2–3% lead, can completely change how the material behaves during manufacturing and in its final application.

2. The 10-Point Evaluation Checklist

UNS (Unified Numbering System)

The most widely used system globally. Brass alloys fall in the C2xxxx–C4xxxx range. For example, C36000 indicates a specific free-cutting brass composition. This system is maintained jointly by ASTM International and SAE.

CDA (Copper Development Association)

Uses the same numbering as UNS for copper alloys. The CDA maintains comprehensive technical data sheets for each alloy number.

ISO / EN Standards

European standards use a different naming convention. For example, C36000 is equivalent to CW614N (CuZn39Pb3) under EN standards. Indian standards (IS) maintained by BIS also designate specific brass compositions aligned with these international systems.

Cross-Reference

3. Major Brass Grades: Detailed Breakdown

C36000 — Free-Cutting Brass

Composition: 61.5% Cu, 35.5% Zn, 3% Pb

The most machined brass alloy on the planet. C36000 is the universal baseline for machinability — all other metals are rated against its score of 100. The 3% lead content acts as a chip breaker, producing small discrete chips during turning and enabling extremely high cutting speeds.

Best for: CNC turned parts, screw-machine products, fittings, valves, connectors, electrical terminals, and any high-volume precision component where machining efficiency is paramount.

C26000 — Cartridge Brass (70/30)

Composition: 70% Cu, 30% Zn

Named for its historical use in ammunition casings, this grade offers the best cold-working characteristics of any brass alloy. It can be deep drawn, stamped, and cold formed without cracking, and develops excellent surface finish after forming.

Best for: Cartridge cases, drawn cups, radiator cores and tanks, lamp fixtures, rivets, springs, and any component manufactured by stamping or deep drawing.

C28000 — Muntz Metal

Composition: 60% Cu, 40% Zn

A high-zinc alpha-beta brass with superior hot-working properties. It offers the highest zinc content of the commonly used brasses, giving it good strength and the ability to be hot forged and extruded efficiently.

Best for: Architectural panels, condenser plates, hot-forged hardware, perforated metal, and large structural brass components.

C46400 — Naval Brass

Composition: 60% Cu, 39.25% Zn, 0.75% Sn

The addition of tin provides significantly improved resistance to dezincification and saltwater corrosion. This makes it the standard material for marine and naval applications where components are in direct or indirect contact with seawater.

Best for: Marine hardware, propeller shafts, turnbuckles, bolts, valve stems, and structural fittings exposed to salt water.

C38500 — Architectural Bronze

Composition: 57% Cu, 40% Zn, 3% Pb

Despite its name, this is technically a leaded brass alloy. It offers excellent hot forging characteristics combined with good machinability, making it ideal for decorative hardware that requires complex shapes.

Best for: Door hinges, lock bodies, architectural trim, decorative hardware, and forged fittings.

C23000 — Red Brass (85/15)

Composition: 85% Cu, 15% Zn

With its high copper content, red brass has excellent corrosion resistance and a distinctive reddish-gold color. It performs well in corrosive water systems and is often used in fire suppression equipment.

Best for: Plumbing pipe, fire sprinkler systems, pump impellers, weather stripping, and artistic metalwork.

C69300 — Lead-Free Silicon Brass

Composition: ~76% Cu, ~22% Zn, ~2% Si

A modern lead-free alloy developed to comply with the U.S. Safe Drinking Water Act. Silicon replaces lead as a machinability enhancer while keeping the alloy safe for potable water contact.

Best for: Plumbing fittings and valves for drinking water systems in the US and regions where lead-free compliance is mandatory.

4. Side-by-Side Grade Comparison Table

5. How Composition Affects Performance

The Role of Copper

Copper is the primary element that provides corrosion resistance, electrical conductivity, and ductility. Higher copper content (above 70%) produces softer, more corrosion-resistant alloys ideal for plumbing. Lower copper content (55–62%) produces harder, stronger alloys better suited for machined components.

The Role of Zinc

Zinc increases hardness and tensile strength. Up to about 37% zinc, the alloy remains in the alpha phase — ductile and cold-workable. Above 37%, the beta phase appears, creating a harder, stronger alloy that is better suited to hot working but less ductile in cold forming.

The Role of Lead

Lead (0.5–3.5%) does not dissolve into the brass matrix. Instead, it forms tiny free particles distributed throughout the alloy. During machining, these particles act as chip breakers — causing the cutting chip to fracture into small, manageable pieces instead of forming long, dangerous strings. This is why leaded brass machines 3–5 times faster than unleaded grades.

The Role of Tin

Tin additions (0.5–1.0%) dramatically improve resistance to dezincification — a corrosion process where zinc leaches out, leaving behind weak, porous copper. This is why naval brass (C46400) contains tin and is specified for seawater service.

6. How to Select the Right Grade

1. Manufacturing Method — If the part will be CNC machined, C36000 is almost always the right starting point. If stamped or deep drawn, C26000. If hot forged, C28000 or C38500.
2. Service Environment — Marine exposure requires C46400. Potable water in the US mandates lead-free grades (C69300). Indoor electrical applications allow the widest range of grades.
3. Mechanical Requirements — High-stress structural components may need the superior tensile strength of C28000 or the fatigue resistance of C46400.
4. Budget & Availability — C36000 is the most readily available and cost-effective grade globally. Specialty grades like C69300 carry a price premium.

7. Lead-Free Brass: Regulations Alternatives

The movement toward lead-free brass has been accelerating, driven by health and environmental regulations in major markets.

Key Regulations

• US Safe Drinking Water Act (SDWA): Limits lead content to 0.25% by weight for components in contact with potable water. Effective since January 2014.
• EU RoHS Directive: Restricts lead in electrical and electronic equipment, though brass fittings have some exemptions.
• California Proposition 65: Requires warning labels on products containing lead above specified thresholds.

Lead-Free Alternatives

• Silicon Brass (C69300): Uses silicon as a chip-breaker substitute for lead. Good machinability (70% of C36000).
• Bismuth Brass: Bismuth mimics lead's chip-breaking behavior. Similar machining performance but higher raw material cost.
• Selenium Brass: Less common, used in specialized applications where other lead substitutes are unsuitable.

If your components are destined for US or EU potable water applications, specify lead-free grades from the start. Retrofitting or re-certifying a product designed for leaded brass is significantly more expensive than selecting the correct grade initially.

8. Recommended Grades by Industry