CuZn39Pb2 vs CuZn39Pb3: Same base brass — CuZn39Pb3 has more Pb for better machinability
CuZn39Pb2 vs CuZn39Pb3
Side-by-side chemical composition and mechanical property comparison.
Overview
CuZn39Pb2
CW612N
Free-cutting brass with 2% lead. Good machinability (80% of CuZn39Pb3) with slightly better cold formability. Used for fittings, valves, electrical connectors, and turned parts where slightly less Pb is acceptable or required by regulation. ≈ UNS C37700.
CuZn39Pb3
2.0401
The most widely used free-cutting brass (machinability index 100%). Excellent for high-speed automatic lathe work. Used for turned parts, faucets, valves, fittings, screws, nuts, electrical connectors, and watch components. Also known as MS58.
| CuZn39Pb2 | CuZn39Pb3 | |
|---|---|---|
| Material Number | CW612N | 2.0401 |
| Category | Copper & Brass | Copper & Brass |
| Standard | EN 12164 | EN 12164 |
Chemical composition (wt%)
| Element | CuZn39Pb2 | CuZn39Pb3 | Overlap |
|---|---|---|---|
| Ni | 0–0.3% | 0–0.3% | OK |
| Cu | 59–62% | 57–59% | Partial |
| Al | 0–0.05% | 0–0.05% | OK |
| Zn | — | — | — |
Mechanical properties
| Property | CuZn39Pb2 | CuZn39Pb3 | Unit |
|---|---|---|---|
| tensile_strength | 410–550 | ≥ 360 | MPa |
| yield_strength | ≥ 250 | ≥ 150 | MPa |
| elongation | ≥ 10 | ≥ 15 | % |
Compatibility Assessment
CuZn39Pb3 (CW614N) has 2.5-3.5% Pb vs 1.6-2.5% for CuZn39Pb2 (CW612N). More Pb = better machinability but worse cold formability and regulatory issues (RoHS/REACH). Choose Pb3 for maximum machinability; Pb2 where regulation or formability matters.
Frequently Asked Questions
Is CuZn39Pb2 the same as CuZn39Pb3?
CuZn39Pb2 and CuZn39Pb3 have a 90% composition overlap. Same base brass — CuZn39Pb3 has more Pb for better machinability
Can I replace CuZn39Pb2 with CuZn39Pb3?
In many cases, yes. The compositions overlap significantly (90%). However, always verify mechanical property requirements and heat treatment compatibility for your specific application.
What is the difference between CuZn39Pb2 and CuZn39Pb3?
The main differences are in the following elements: Cu, Pb. CuZn39Pb2 is a Copper & Brass grade, while CuZn39Pb3 is a Copper & Brass grade.
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Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.