Application Guide 01

Plumbing &
Potable Water

Brass alloy selection for drinking water contact — DZR requirements, lead limits, and approval routes in every major market.

DZR Required WRAS · KIWA · DVGW · NSF 61 Lead-free mandated
The Core Challenge

Two Requirements in One Grade

Plumbing brass must satisfy two independent requirements simultaneously:

DZR — dezincification resistance is mandatory for pressure-bearing fittings in all regulated potable water systems. Alloys with Zn >15% in aggressive water conditions will fail without it.
Lead-free — every major market now restricts or eliminates leaded brass from drinking water contact. WRAS, KIWA, ACS, DVGW, NSF 61, and AB 1953 all effectively require Pb ≤ 0.10%.

Traditional CW617N (leaded DZR-capable via CW602N) was once standard for plumbing. Today, CW724R / C69300 (EU/UK & US low-lead) and C6802 (US/Canada) are the dominant choices — both are inherently DZR via silicon kappa-phase and fully RoHS/lead-free compliant.

Market by Market

Lead Limits

EU (DWD 2020/2184)5 μg/L by 2036
UK (WRAS)0.10 μg/L (extract)
France (ACS)≤ 1 μg/L migration
Germany (DVGW W 270)0.10 μg/L
US EPA (action level)15 μg/L (action)
California (AB 1953)≤ 0.25% wtd avg Pb
Alloy Comparison

Plumbing Alloy Selection Table

AlloyDZRLeadRoHSMachinabilityWRAS/KIWA/DVGWNSF 61Best For
CW724R ✓ Intrinsic ≤ 0.10% ✓ Free 80% ✓ Approvable Via B371 EU/UK/EU markets, primary DZR lead-free grade
C6802 ✓ Intrinsic ≤ 0.09% ✓ Free 78% EU equiv. ✓ Certified US/Canada, NSF 61 required, AB 1953
CW602N ✓ As-inhibited 1.5–2.5% Ex 6(c) 62% Market-dep. Legacy systems, non-DW industrial water circuits
C27450 ✗ No ≤ 0.09% ✓ Free 55% Market-dep. Non-pressure water contact, gas valves, low-DZR-risk
CW617N 1.6–2.5% Ex 6(c) 100% Not suitable for potable water contact
Decision: Market

EU / UK / Aus markets?

For fittings destined for European, UK, or Australian regulated plumbing markets, CW724R (CuZn21Si3P) is the primary choice.

CW724R achieves DZR intrinsically through its silicon kappa-phase microstructure. It is fully RoHS-free (Pb ≤ 0.10%) and can be approved under WRAS, KIWA, ACS, and DVGW — the four major EU/UK approval bodies.

Machinability: 80% — slower than CW617N but excellent for CNC brass fittings.

Decision: Market

US / Canada / Mexico?

For North American markets, C6802 (CuZn17Si4) per ASTM B371 is the standard. Certified to NSF/ANSI 61 and compliant with California AB 1953.

C6802 has higher silicon (3.0–4.5%) than CW724R, giving it an even more pronounced kappa-phase structure. Its lower Cu content (~81%) makes it slightly more cost-effective. NSF 61 certification is product-specific — the fitting manufacturer holds the certification.

Machinability: 78% — comparable to CW724R for high-volume CNC production.

Decision: Legacy

Replacing CW602N?

CW602N (arsenic-inhibited DZR) was the traditional DZR grade before silicon brasses dominated. It still contains lead (1.5–2.5%) and is subject to RoHS Exemption 6(c).

For new designs targeting potable water contact, substitute CW724R (EU/UK) or C6802 (US). CW602N remains valid for non-potable DZR applications such as industrial cooling water circuits where lead restrictions do not apply.

CW602N maintains its value in marine and industrial water systems outside drinking water scope.

Component Applications

Common Plumbing Components & Alloy Recommendations

ComponentRecommended AlloyKey Requirement
Compression fittings (EU)CW724RDZR + WRAS/KIWA/DVGW approval
Push-fit fittings (EU)CW724RDZR + dimensional precision
Ball valve bodies (EU)CW724RDZR + hot-forge capable + lead-free
Compression fittings (US)C6802NSF 61 + AB 1953 compliant
Gate/ball valves (US)C6802NSF 61 + ASTM B371
Gas meter fittingsC27450Low lead + machinability
Industrial water circuitsCW602NDZR (non-potable scope)
Copper tube / fittingsC11000Highest corrosion resistance, ≥99.9% Cu
Plumbing Fittings

DZR brass fittings, export-ready.

Brassland manufactures CW724R and C6802 fittings with EN 10204 3.1 certificates. Tell us your approval target and we'll specify the right grade.

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FAQ

Plumbing & potable-water brass — common questions

Which brass is best for potable water in the EU and UK?
CW724R silicon brass — dezincification-resistant (DZR), low-lead, and approvable to WRAS, KIWA, DVGW and ACS. It supports the EU Drinking Water Directive 2020/2184 lead limits.
Which brass is used for potable water in the US and Canada?
C6802 silicon brass — certified to NSF/ANSI 61 and meeting the AB 1953 / NSF 372 0.25% weighted-average lead limit on wetted surfaces. See our Prop 65 / lead notes.
What is DZR brass and why does it matter for plumbing?
DZR (dezincification-resistant) brass stops zinc selectively leaching out in aggressive water, which would otherwise leave a weak, porous copper residue and contaminate the water. Resistance is verified by the ISO 6509-1 test — see corrosion & DZR.
Is standard yellow brass (CW617N) suitable for drinking water?
Standard CW617N yellow brass is not dezincification-resistant and is not approved for potable-water contact in the EU/UK. Specify a DZR or lead-free grade — CW724R (EU/UK) or C6802 (US/Canada).
From Guide to Production

Need plumbing parts made?

This guide covers alloy selection. To have components machined to your drawing, see the matching manufacturing pages:

Sources & References

Verify this datasheet against the primary source

Composition 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.

Copper Development Association
CDA alloy database — composition & properties
European Copper Institute
Copper Alliance EU — alloy designation system
MatWeb
Independent material property database
SteelNumber.com
EN material designation cross-reference
CEN / CENELEC
EN 12164, EN 12165, EN 12167, EN 12420
ASTM International
ASTM B16, B124, B283, B371 specifications
ISO 6509-1:2014
Dezincification test method (CuCl₂)
EU RoHS Directive 2011/65
Annex III Exemption 6(c) — valid to 30 Jun 2027
ECHA REACH SVHC List
Lead is on the candidate list (Article 33)
WRAS (UK)
Water Regulations Advisory Scheme approval search
NSF/ANSI/CAN 61
Drinking water system components (US/CA)
Brassland — Standards Guide
Plain-English explainer for every standard above

Last reviewed: May 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.