Application Guide 02

Electrical &
Electronics

RoHS compliance, conductivity hierarchy, and alloy selection for connectors, busbars, terminals, and EMI shielding.

RoHS Critical 2011/65/EU · Exemption 6(c) Conductivity First
Property Hierarchy

Conductivity — The First Filter

In electrical applications, electrical conductivity (% IACS) is the primary material selection criterion. Brass is far less conductive than copper — use brass only where conductivity is not the limiting constraint.

C11000 (Cu-ETP)
≥100% IACS
CuZn37
~27% IACS
CW724R
~16% IACS
CW617N
~15.5% IACS
Rule of thumb: If the component is primarily carrying current (busbar, transformer winding, motor terminal), specify C11000 — or C14500 tellurium copper when the part needs significant machining. If it is primarily a structural fitting, fastener, or housing that also carries current, brass is appropriate.
RoHS in EEE

The Key Constraint

All components in electrical and electronic equipment (EEE) sold in the EU must comply with RoHS 2 (2011/65/EU). For brass components:

Pb ≤ 0.10%✓ No exemption
Pb > 0.10%Exemption 6(c) until Jun 2027
For new EEE designs with long product lifespans, consider lead-free grades (CW724R, CuZn37, C27450) to avoid re-engineering when Exemption 6(c) expires.
REACH

Article 33 for EEE

All leaded brass components in EEE require REACH Article 33 SVHC communication (lead >0.10% w/w). Brassland provides declarations of conformance with all shipments of leaded alloys.

Alloy Selection

Electrical & Electronic Applications — Alloy Guide

AlloyConductivityRoHSMachinabilityCold FormingBest Application
C11000 ≥ 100% IACS ✓ Free ~20% Excellent Busbars, motor terminals, transformer windings, grounding
C14500 ~93% IACS ✓ Free 85% Good Machined connectors, terminals, contact pins, welding-torch parts — copper conductivity with screw-machine productivity
CuZn37 ~27% IACS ✓ Free 50% Excellent (α-phase) Stamped connectors, spring contacts, EMI shielding, transformer laminations
CW724R ~16% IACS ✓ Free 80% Moderate CNC connector housings, RoHS-free screw-machined parts, terminal blocks
C27450 ~24% IACS ✓ Free 55% Good RoHS-critical turned parts, switch components, moderate conductivity needed
CW617N ~15.5% IACS Ex 6(c) 100% Moderate High-volume CNC connectors/housings where RoHS Ex 6(c) accepted
Busbars & Conductors

Always C11000

For current-carrying conductors — busbars, motor terminals, transformer windings, battery connections — C11000 (Cu-ETP) is the only viable copper alloy. No brass comes close to its ≥100% IACS conductivity.

Key properties: ≥100% IACS, thermal conductivity 390 W/(m·K), RoHS free, weldable, soft-annealable for complex bending. Avoid hydrogen embrittlement risk in reducing atmospheres — specify Cu-OF (C10200) in such cases.
Stamped Connectors

CuZn37 (CW508L)

For stamped, drawn, or deep-formed electrical contacts — socket contacts, spring clips, shielding cans — CuZn37 is the standard. Its all-alpha microstructure gives exceptional cold formability (elongation ≥45%) with zero lead.

ASTM equivalent: C26000 Cartridge Brass — widely specified in automotive wiring harness and consumer electronics connector standards.
CNC Connector Bodies

CW724R or CW617N

For machined connector housings, terminal blocks, and insert bodies, the choice depends on RoHS requirements. CW724R for full RoHS compliance (no exemption needed). CW617N for maximum machinability where Exemption 6(c) is acceptable.

2027 planning: New connector designs should use CW724R now — avoid redesign when Exemption 6(c) expires in June 2027.
Electrical Brass Components

RoHS-compliant. Precision-machined.

We supply RoHS declarations, EN 10204 3.1 certificates, and REACH Article 33 notifications as standard with all EEE-grade orders.

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FAQ

Electrical & electronics brass — common questions

Which material is used for busbars and high-current contacts?
C11000 electrolytic tough-pitch copper, at about 100% IACS, is the standard choice for busbars and high-current contacts. Brasses conduct far less, so copper is specified wherever current-carrying capacity drives the design.
Which brass is used for connectors and terminals?
Free-machining CW617N (and CW614N) are used for connector bodies, terminals and pins. For RoHS-critical electrical and electronic equipment, lead-free CW724R silicon brass is used.
Is brass RoHS compliant in electronics?
Inside EEE, leaded brass relies on RoHS Annex III exemption 6(c) (copper alloy up to 4% lead), while lead-free CW724R and C11000 copper are compliant without any exemption.
What is the electrical conductivity of brass versus copper?
Common brasses conduct roughly 25–28% IACS, while C11000 copper is about 100% IACS — so copper is chosen for current-carrying parts and brass for connector bodies and structural hardware.
From Guide to Production

Need electrical 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.