Weight %. The α+β duplex structure at ~40% Zn is what makes this grade flow so well in closed dies.
| Element | Symbol | Min % | Max % | Typical % |
|---|---|---|---|---|
| Copper | Cu | 57.0 | 59.0 | 58.0 |
| Zinc | Zn | Balance | ~39.5 | |
| Lead | Pb | 1.6 | 2.5 | 2.0 |
| Iron | Fe | — | 0.30 | 0.10 |
| Nickel | Ni | — | 0.30 | 0.05 |
| Property | Condition | Value | Unit |
|---|---|---|---|
| Tensile Strength (Rm) | R360 annealed | 360–470 | MPa |
| Tensile Strength (Rm) | R430 half-hard | 430–540 | MPa |
| Proof Stress (Rp0.2) | R360 | ≥140 | MPa |
| Elongation (A) | R360 | ≥18 | % |
| Hardness | R360 typical | 95–115 | HB |
| Machinability | vs C36000 = 100 | ~90% | — |
| Density | — | 8.47 | g/cm³ |
| Thermal Conductivity | — | ~123 | W/(m·K) |
| Melting Range | solidus–liquidus | 895–920 | °C |
| Standard | Designation |
|---|---|
| EN (Europe) | CW617N / CuZn40Pb2 |
| UNS / ASTM (USA) | C37700 — Forging Brass |
| BS (UK legacy) | CZ122 |
| DIN (Germany) | CuZn40Pb2 / Ms58 |
| JIS (Japan) | C3604 (close — verify Pb) |
| GB (China) | HPb59-1 (close) |
CW617N (CuZn40Pb2) is the workhorse hot-working brass of EN 12164/12165: its alpha-beta structure flows beautifully at forging temperature, making it the standard grade for hot-forged valve bodies, fitting bodies and stamped parts, which are then finish-machined — it machines at roughly 90% of the C36000/CW614N free-cutting benchmark.
Yes, under RoHS Annex III Exemption 6(c), which permits up to 4% lead in copper alloys and is currently valid to 30 June 2027. Where outright lead-free material is mandated — e.g. potable water wetted surfaces under US NSF 372 or the EU Drinking Water Directive — specify CW724R or C6802 silicon brass instead.
Choose CW617N when the part starts life as a hot forging or stamping; choose CW614N (CuZn39Pb3) when the part is machined entirely from drawn rod, since its higher lead gives the best chip-breaking on CNC and Swiss lathes. Both are RoHS-compliant under Exemption 6(c).
The closest equivalents are C37700 forging brass (US, ASTM) and CZ122 (former UK BS designation). Composition is specified in EN 12164 (rod) and EN 12165 (forging stock); Brassland supplies EN 10204 Type 3.1 mill certificates with every lot.
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Request a QuoteComposition ranges, mechanical properties, machinability ratings and regulatory data on this page are cross-referenced against the publishers below. Tolerances and minimum values are taken from the relevant published standard at the time of writing — for procurement specification, always reference the current published edition.
Last reviewed: June 2026. EN/ISO/ASTM standards are updated periodically. This datasheet reflects the editions listed; for safety-critical or contract-critical applications, always verify against the current published edition of the standard. For project-specific deviations or supplier-specific composition windows, request a Type 3.1 mill certificate (EN 10204) with your order.