Weight %. Balanced for hot die forging: enough β-phase for flow at forging temperature, enough Pb for clean finish machining.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Copper | Cu | 58.0 | 61.0 |
| Zinc | Zn | Balance | |
| Lead | Pb | 1.5 | 2.5 |
| Iron | Fe | — | 0.30 |
Bars show the range from the table: bar length at mid-range, zinc as the remainder.
Typical rod values by section size and cold work — strength falls as the section grows. The mill certificate reports the values of the supplied rod.
| Property | Condition | Value | Unit |
|---|---|---|---|
| Tensile / Yield (0.5 % ext.) / Elongation | rod M30 (as hot extruded), 1 in (25 mm) | ~359 / ~138 / ~45 | MPa / MPa / % |
| Hardness | rod M30, 1 in (25 mm) | ~78 | HRF |
| Hot Forgeability | CDA rating (C37700 = 100) | 100 | index |
| Machinability | CDA rating (C36000 = 100) | 80 | index |
| Density | at 20 °C | 8.44 | g/cm³ |
| Electrical Conductivity | at 20 °C | 27 | %IACS |
| Thermal Conductivity | at 20 °C | 119 | W/(m·K) |
| Thermal Expansion | CDA, 20–300 °C | 20.7 | ×10⁻⁶/K |
| Melting Range | solidus–liquidus | 882–893 | °C |
| Standard | Designation |
|---|---|
| UNS / ASTM (USA) | C37700 — ASTM B283 / B124 |
| EN — equivalent | CW608N / CuZn38Pb2 |
| EN — equivalent | CW612N / CuZn39Pb2 |
| EN — forging cousin | CW617N / CuZn40Pb2 |
| BS (UK legacy) | CZ120 (as CW608N) · CZ128 (as CW612N) |
| JIS (Japan) — nearest | C3771 — JIS H3250 forging brass (Cu 57–61, Pb 1.0–2.5) |
| Trade name | Forging Brass |
C37700 — forging brass — is the standard North American grade for hot-pressed brass die forgings per ASTM B283 (forgings) and B124 (forging rod). With 58–61% copper and 1.5–2.5% lead, it is rated 100 for hot forgeability and about 80% for machinability, so forged blanks finish-machine cleanly.
C37700 has two EN equivalents: CW608N (CuZn38Pb2) and CW612N (CuZn39Pb2), whose copper and lead ranges both lie inside the C37700 limits; their legacy British designations are CZ120 and CZ128. European forged fittings are also commonly made in CW617N (CuZn40Pb2, legacy BS CZ122), which overlaps C37700 only between 58 and 59 % copper — its UNS equivalent is C38000. Confirm which grade your drawing specifies.
Forging pays off on heavy sections, large hex bodies, and asymmetric shapes where bar machining would turn most of the material into swarf. It also gives an unbroken grain flow around the part shape. Thin, long, or high-precision turned geometries usually stay cheaper machined from bar — we advise per drawing at quotation.
Yes — hot-forged brass components are supplied made to your drawing (forging through our qualified forging partners, with finish CNC machining and inspection in-house). The exact grade — C37700 or its EN equivalents — and a Type 3.1 mill certificate are confirmed at quotation.
Write the standard and designation together, for example “ASTM B283 – C37700”. State the condition or a minimum property on the drawing when it matters; the table above gives the standard values. Tolerances follow ISO 2768-m unless the title block says otherwise.
The mill’s EN 10204 Type 3.1 inspection certificate for the alloy lot reports the measured chemical composition and mechanical test results. Brassland adds a Certificate of Conformity for the order and RoHS and REACH declarations at no charge; PPAP Level 1–3 packages are available for OEM qualification.
ASTM B283 – C37700. The EN equivalents are CW608N / CuZn38Pb2 and CW612N / CuZn39Pb2.Primary source: Copper Development Association C37700.
Hot-forged blanks, finish-machined and inspected in Jamnagar. ISO 9001:2015. Quote within 24 hours.
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: September 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.
Brassland machines C37700 into brass turned parts and CNC machined components to your drawing in Jamnagar, India, including precision turned brass components on 28+ Swiss-type lathes, with an EN 10204 3.1 certificate on every shipment.