Weight %. Higher Cu and Si than CW724R; the same kappa-phase chip-breaking and dezincification resistance.
| Element | Symbol | Min % | Max % | Typical % |
|---|---|---|---|---|
| Copper | Cu | 80.0 | 83.0 | 81.5 |
| Zinc | Zn | Balance | ~15 | |
| Silicon ✓ | Si | 3.0 | 4.5 | 3.8 |
| Lead (max) ✓ | Pb | — | 0.09 | ≤0.05 |
| Manganese | Mn | — | 0.50 | 0.10 |
| Property | Condition | Value | Unit |
|---|---|---|---|
| Tensile Strength (Rm) | by temper | 483–620 | MPa |
| Yield Strength | 0.5% ext. | ≥207 | MPa |
| Elongation | typical | ≥15 | % |
| Hardness | typical | 120–155 | HRB |
| Machinability | vs C36000 = 100 | ~78% | — |
| Density | — | 8.69 | g/cm³ |
| Thermal Conductivity | — | ~65 | W/(m·K) |
| Melting Range | solidus–liquidus | 870–900 | °C |
| Standard | Designation |
|---|---|
| UNS / ASTM (USA) | C6802-type — ASTM B371 |
| EN sibling | CW724R / CuZn21Si3P |
| UNS sibling | C69300 / CuZn21Si3P |
| Chemical designation | CuZn17Si4 |
| DZR test method | ISO 6509-1 (CuCl₂) |
C6802 (CuZn17Si4) is an ASTM B371 silicon brass with lead at or below 0.09%. Like CW724R it gains intrinsic dezincification resistance and chip-breaking from its kappa-phase microstructure, rating around 78% machinability — close to leaded brass performance without the lead.
C6802 is NSF 61 listed for potable water contact and meets the NSF/ANSI 372 weighted-average lead limit of 0.25%, making it the natural choice for fittings destined for the US and Canadian markets. Final NSF 61 listing applies to the finished product, which the buyer or brand owner registers.
They are functionally similar. Choose C6802 when your specification or market is ASTM/NSF-driven (North America); choose CW724R (CuZn21Si3P) when the drawing references EN 12164 or European approvals like WRAS, ACS or KIWA. Brassland machines both routinely and can quote either against your drawing.
Yes — fully, with no exemption needed, since lead is at or below 0.09%. That also future-proofs parts against the tightening of RoHS Exemption 6(c) expected after June 2027.
The NSF-market silicon brass, made to your drawing. 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: 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.