C36000 VS C38500 copper material

1. Chemical Composition (Primary Difference)

The core distinction lies in their copper (Cu), zinc (Zn), and lead (Pb) content-elements that directly determine their performance. The following values comply with industry standards (e.g., ASTM B16/B16M for brass):

Element	C36000 (Free-Cutting Brass)	C38500 (Leaded Nickel Brass)	Key Note
Copper (Cu)	60.0 – 63.0%	56.0 – 59.0%	C36000 has higher copper content, enhancing corrosion resistance and ductility.
Zinc (Zn)	Balance (≈35–38%)	Balance (≈35–38%)	Similar zinc content (the main alloying element for brass strength).
Lead (Pb)	2.5 – 3.7%	2.0 – 3.0%	C36000 has slightly more lead, boosting machinability (lead acts as a "lubricant" during cutting).
Nickel (Ni)	0.5% Max (Trace)	1.5 – 2.5%	Unique to C38500: Nickel is intentionally added to improve strength, wear resistance, and corrosion resistance (especially in harsh environments like saltwater).
Iron (Fe)	0.15% Max	0.15% Max	Low iron content to avoid brittleness (common in brass alloys).

2. Mechanical Properties

Their composition differences translate to distinct strength, hardness, and ductility:

Property (Annealed Condition)	C36000	C38500	Key Takeaway
Tensile Strength	~414 MPa (60,000 psi)	~483 MPa (70,000 psi)	C38500 is ~16% stronger, thanks to nickel addition.
Yield Strength (0.2% Offset)	~172 MPa (25,000 psi)	~241 MPa (35,000 psi)	C38500 has much higher yield strength, meaning it resists permanent deformation better under load.
Brinell Hardness (HB)	~85	~110	C38500 is significantly harder, improving wear resistance for moving parts.
Elongation (in 50 mm)	~30%	~20%	C36000 is more ductile (easier to bend or form) due to higher copper and lower nickel content.

3. Machinability

Both are "free-cutting" brass (designed for high-speed machining), but their performance varies slightly:

C36000: Known as "the workhorse of free-cutting brass," its higher lead content (2.5–3.7%) reduces tool wear and produces clean, chip-free cuts. It is ideal for high-volume, precision machining (e.g., screws, nuts, and small components) where speed and tool life are critical.

C38500: Its lower lead content (2.0–3.0%) slightly reduces machinability compared to C36000, but it still performs well in most machining operations. The tradeoff is better strength and durability-making it suitable for parts that require both machinability and structural integrity.

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4. Corrosion Resistance

Corrosion resistance is critical for applications exposed to moisture or chemicals:

C36000: Offers good general corrosion resistance (e.g., in air, freshwater, or mild chemicals) due to its high copper content. However, it is less resistant to saltwater or acidic environments.

C38500: Nickel addition drastically improves its corrosion resistance-especially against dezincification (a common failure mode in brass where zinc leaches out, leaving a porous copper structure) and saltwater corrosion. This makes it suitable for marine hardware, plumbing parts in coastal areas, or chemical processing components.

5. Typical Applications

Their unique properties make them suited for different use cases:

Alloy	Common Applications
C36000	- Precision fasteners (screws, bolts, nuts) - Electrical connectors and terminals - Plumbing fittings (freshwater only) - Small machined components (e.g., watch parts, valve stems)
C38500	- Marine hardware (boat cleats, fittings, propeller shafts) - High-strength fasteners for industrial equipment - Plumbing parts in coastal or corrosive environments - Gears, bearings, and wear-resistant components