Pure Copper — Electrical Grade

C11000

Cu-ETP / CW004A — Electrolytic Tough Pitch Copper

99.90% minimum copper — the standard electrical grade, at ≥100% IACS conductivity. Essential for busbars, terminals, transformer parts and heat exchangers where conductivity is non-negotiable. Machinability ≈20% — sharp tooling and flood coolant required. EN designation: CW004A.

⚡ ≥100% IACS
🥇 99.90% Min Cu
✅ RoHS — No Exemption
📋 ASTM B152 / B187
🌍 ≡ CW004A · C101
≥100%
IACS electrical conductivity
99.90%
Minimum copper content
390
Thermal conductivity, W/(m·K)
~20%
Machinability — plan sharp tooling
Chemical Composition

C11000 — Cu-ETP Limits

Weight %. Electrolytic tough pitch: minimum 99.90% Cu (Ag counted in), with controlled residual oxygen.

ElementSymbolMin %Max %Typical %
Copper (incl. Ag)Cu99.9099.95
OxygenO0.010.05~0.04
Lead (max)Pb0.005≤0.003
Total impurities0.10
Copper (Cu)
~99.95%
Mechanical Properties

Typical (soft → hard)

PropertyConditionValueUnit
Tensile Strength (Rm)soft → hard200–340MPa
Proof Stress (Rp0.2)soft → hard70–280MPa
Elongation (A)by temper6–45%
Electrical Conductivityannealed≥100% IACS
Thermal Conductivity390W/(m·K)
Machinabilityvs C36000 = 100~20%
Density8.90g/cm³
Melting Point1083°C
Typical Applications
  • Busbars, bars and high-current connectors
  • Electrical terminals, lugs and grounding hardware
  • Transformer and motor components
  • Heat-exchanger and thermal parts
  • Tin- or silver-plated contact parts
Why choose C11000?

When conductivity is the spec

  • ≥100% IACS — the reference conductor; nothing in the brass family comes close
  • 99.90% min Cu — ASTM B152/B187 standardised, EN twin CW004A
  • RoHS free — no restricted substances
  • Gummy to machine (~20%) — for machined connector geometry consider C14500 tellurium copper
  • Hydrogen embrittlement caveat — in reducing atmospheres above ~370°C specify oxygen-free C10200 instead
RoHS & Compliance

Compliance Status

RoHS
✓ Fully Compliant
Lead-free by composition — no exemption needed.
Machining
Plan for ~20% Rating
High positive rake, flood coolant, light feeds. Long stringy chips and built-up edge are the risks.
Free-machining copper
C14500 — 93% IACS at 85% machinability
International Equivalents

C11000 Cross-Reference

StandardDesignation
UNS / ASTM (USA)C11000 — ASTM B152, B187
EN (Europe)CW004A / Cu-ETP
BS (UK legacy)C101 / C102
DIN (Germany)Cu-ETP / E-Cu57
JIS (Japan)C1100
C11000 is susceptible to hydrogen embrittlement in reducing atmospheres (brazing, annealing in H₂). For those processes specify oxygen-free C10200 — 20–40% costlier but immune.
Free-machining Cu →
C14500
Tellurium copper — 93% IACS, 85% machinability
Electrical brass →
CuZn37
Cartridge brass — stamped connectors, ~27% IACS
↑ All alloys
Materials Library
Frequently Asked Questions

C11000 — common questions

What is C11000 copper used for?

C11000 (Cu-ETP / CW004A) is electrolytic tough pitch copper, minimum 99.90% Cu, with 100% IACS electrical conductivity. It is the default material for busbars, terminals, transformer parts, grounding hardware and heat-exchanger components where conductivity matters more than strength.

How difficult is C11000 to machine compared with brass?

Pure copper is gummy: it rates around 20% machinability against free-machining brass, with long stringy chips and built-up edge risk. Expect roughly 70% lower cutting speeds than CW614N, very sharp tooling and high-pressure coolant. Brassland machines C11000 terminals and contacts routinely on CNC and Swiss lathes.

Is C11000 RoHS compliant and suitable for electrical use?

Yes — C11000 is lead-free by composition, so it is RoHS compliant without exemptions, and its 100% IACS conductivity makes it the reference conductor material. Silver-plating or tin-plating can be added for contact surfaces.

What standards cover C11000?

Plate, sheet and bar are specified in ASTM B152, with the European equivalent designated CW004A (Cu-ETP) under EN standards. Brassland supplies parts with EN 10204 Type 3.1 mill certificates confirming purity and temper.

C11000 machined in Jamnagar

Busbars, terminals and contacts at 100% IACS, made to your drawing. ISO 9001:2015. Quote within 24 hours.

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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 C11000 alloy datasheet — composition & properties
ASTM International
US specifications for copper-alloy rod, bar and forgings
MatWeb
Independent material property database — C36000 by temper
European Copper Institute
Copper Alliance EU — EN alloy designation system
SteelNumber.com
EN material designation cross-reference (CW603N/CW614N)
CEN / CENELEC
EN 12164, EN 12165, EN 12167 — EN brass rod standards
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)
NSF/ANSI/CAN 61
Drinking water system components (US/CA)
Brassland — Standards Guide
Plain-English explainer for every standard above

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.