In the world of copper alloys, C26000 (Cartridge Brass) and C36000 (Free-Cutting Brass) are two essential yet fundamentally different materials. They are often compared by engineers, purchasers, and manufacturers, but their core difference can be summarized in one sentence: C26000 is the alloy designed for cold forming, while C36000 is the alloy engineered for machining. Choosing the wrong one can lead to poor production efficiency, higher costs, and even part failure.
Different Design Purposes
| Feature | C26000 (Cartridge Brass / 70-30 Brass) | C36000 (Free-Cutting Brass) |
|---|---|---|
| Primary Purpose | Cold Forming | High-Speed Machining |
| Key Composition | Cu ~70%, Zn ~30% (binary α-phase brass). Lead (Pb) is minimized (<0.07%). | Cu ~61%, Zn ~35%, Lead (Pb) ~3% (intentionally added). |
| Industry Nickname | "The Former's Choice" | "The Machinist's Friend" |
Detailed Property Comparison
Mechanical & Physical Properties
| Property | C26000 | C36000 |
|---|---|---|
| Formability (Cold Work) | Excellent. The benchmark for deep drawing, stamping, bending, and spinning. Its single-phase α structure allows severe deformation without cracking. | Poor to None. The added lead particles create brittleness. It will crack if subjected to significant bending or stamping. |
| Machinability | Fair (rated ~20% of C36000). Produces long, stringy chips that can tangle tools. Requires appropriate tool geometry and speeds. | Exceptional (rated 100%, the industry standard). Lead acts as an internal chip breaker, producing small, broken chips that clear easily. Enables high speeds, low tool wear, and excellent surface finishes. |
| Tensile Strength | Good, can be increased via cold work. Annealed: ~325 MPa | Slightly higher in the as-supplied condition. Annealed: ~340 MPa |
| Ductility | Very High (Annealed: >50% elongation) | Low (Annealed: ~25% elongation) |
| Corrosion Resistance | Good general resistance. Can be susceptible to dezincification in specific environments. | Slightly lower due to the multi-phase structure and lead content. Not recommended for corrosive environments. |
Why Such a Difference?
C26000: A single-phase (α) solid solution. Its uniform crystal structure is like soft, pliable dough, allowing grains to slide past each other during deformation.
C36000: A two-phase (α + β) structure with dispersed lead particles. The lead is insoluble and forms tiny, soft inclusions that break up the chip during cutting but also act as internal stress concentrators, causing brittleness during forming.
Choosing the Right Alloy
Use C26000 When:
The part is made by stamping, deep drawing, or bending (e.g., electrical connectors, cartridge cases, heat exchanger fins, decorative trim, complex brackets).
Good overall corrosion resistance and electrical conductivity are needed alongside formability.
The part requires subsequent plating or polishing (its uniform structure provides a better base).
Use C36000 When:
The part is made primarily by turning, drilling, milling, or threading on CNC or screw machines (e.g., precision fittings, valves, gears, nuts, bolts, couplings).
High production speed, tight tolerances, and a superior surface finish are critical.
The part is a small, complex mechanical component where machining is the most cost-effective manufacturing method.
Cost & Practical Considerations
Material Cost: C36000 is generally slightly more expensive per kilogram due to its lead content and specialized production.
Total Part Cost: This is the critical factor. For a complex stamped part, using C26000 will be drastically cheaper overall. For a part requiring extensive milling and drilling, using C36000 will save significantly on machining time, tool wear, and scrap rates, making it the more economical choice despite its higher raw material cost.
Our factory
Our factory specializes in the production and manufacturing of high-quality copper products. We operate a comprehensive, end-to-end production line equipped with advanced continuous casting and rolling mills, precision drawing machines, high-speed rolling mills, and automated heat treatment systems. We professionally produce a wide range of copper tubes, plates, bars, wires, and foils. A strict quality inspection system is implemented throughout the entire process, from raw material intake to finished product delivery. Supported by precision instruments such as spectrometers, metallographic microscopes, tensile testing machines, eddy current flaw detectors, and laser dimension gauges, we ensure that our products fully comply with international and domestic standards-including ASTM, EN, JIS, and GB-in terms of chemical composition, mechanical properties, dimensional accuracy, and surface quality. We are committed to providing global customers with stable, reliable, and fully-specified copper material solutions.
copper product packaging
Our products are packaged using professional, customized industrial packaging solutions to ensure they remain intact during long-distance transportation and multiple handlings. For long products such as copper tubes and bars, we use sturdy waterproof wooden crates or metal-frame boxes for secure fixing and protection. Copper plates and foils are individually wrapped with anti-rust paper, then packed into steel-edged boxes or on pallets with reinforced hard corners. Copper wires are wound with moisture-proof film and neatly coiled onto custom-designed reels or placed in wooden cases. All packaging is clearly marked according to customer requirements with shipping marks, specifications, batch numbers, and handling symbols. Desiccants can also be placed inside the packages when needed, providing complete protection against rust, moisture, and impact throughout the entire journey from production to the destination port.
