Leaded Free-Machining Brass — US Benchmark Grade

C36000

Free-Cutting Brass 360 — CuZn36Pb3 / ASTM B16

The North American standard for high-speed screw machining — and the alloy that defines the copper-alloy machinability scale at 100%. 60–63% Cu with 2.5–3.7% Pb for self-breaking chips and excellent surface finish. EN equivalent: CW603N (CuZn36Pb3); commercially cross-referenced to CW614N.

⚙️ 100% Machinability Benchmark
📋 ASTM B16
⚠️ RoHS Ex 6(c)
🌍 ≡ CW603N · CZ124
100%
Machinability — the rating benchmark
60–63%
Copper content (ASTM B16)
2.5–3.7%
Lead — chip-breaking additions
Ex 6(c)
RoHS — valid to Jun 2027
Chemical Composition

C36000 — ASTM B16 Limits

Weight %. Slightly higher Cu and wider Pb window (max 3.7%) than EN 12164 leaded grades — check your spec when substituting CW614N (Pb max 3.5%).

ElementSymbolMin %Max %Typical %
CopperCu60.063.061.5
ZincZnBalance~35.4
LeadPb2.53.73.1
IronFe0.350.10
Copper (Cu)
~61.5%
Zinc (Zn)
~35.4%
Lead (Pb)
~3.1%
Mechanical Properties

Typical for rod (varies by temper)

PropertyConditionValueUnit
Tensile StrengthO60 soft → H02 half-hard340–470MPa
Yield StrengthO60 soft → H02 half-hard125–310MPa
ElongationH02 half-hard, typical~25%
HardnessH02 half-hard, typical~78HRB
Machinabilityvs C36000 = 100100%
Elastic Modulus~97GPa
Density8.49g/cm³
Thermal Conductivity~115W/(m·K)
Melting Rangesolidus–liquidus885–900°C
Typical Applications
  • High-volume screw-machine products — fittings, adaptors, unions, plugs
  • Electrical and electronic connectors, terminals, and pins
  • Fastener components — nuts, standoffs, inserts, set screws
  • Sensor bodies, gauge and instrument components, meter parts
  • Gears, pinions, and small precision mechanism parts
Why choose C36000?

The alloy that sets the machinability scale

  • 100% machinability rating — C36000 is the reference grade against which all copper alloys are rated
  • Pb 2.5–3.7% — self-breaking chips, low cutting forces, excellent surface finish at very high spindle speeds
  • ASTM B16 standardised — the default grade on North American drawings for screw-machine parts
  • Higher Cu (60–63%) than CW614N — slightly better corrosion resistance and a warmer colour
  • Limited cold-forming — like all high-Pb grades, not suited to bending, staking, or heavy cold work
RoHS & Compliance

Compliance Status

RoHS
Exemption 6(c) Required
Pb 2.5–3.7% — within the 4% copper-alloy allowance. Valid to 30 June 2027.
Drinking Water (US)
Not Suitable — Wetted Parts
NSF/ANSI 372 limits weighted Pb to 0.25% in potable systems. Use a lead-free grade instead.
Lead-free alternatives
CW724R · C6802 — silicon brass, 78–80% machinability
International Equivalents

C36000 Cross-Reference

StandardDesignation
UNS / ASTM (USA)C36000 — ASTM B16
EN — closest matchCW603N / CuZn36Pb3
EN — commercialCW614N / CuZn39Pb3
BS (UK legacy)CZ124
JIS (Japan)C3604 (close)
Trade name360 Brass / Free-Cutting Brass
⚠️ Strictly by composition, C36000 (CuZn36Pb3) maps to CW603N. Commercial cross-reference tables often list CW614N (CuZn39Pb3) — machining behaviour is near-identical, but Cu content and Pb limits differ slightly. Confirm which your spec requires.
← EN sibling
CW614N
CuZn39Pb3 — European free-machining workhorse
Lead-free cousin →
CuZn37
Cartridge brass — same Zn level, no Pb
↑ All alloys
Materials Library
Frequently Asked Questions

C36000 — common questions

What is C36000 brass?

C36000 — also sold as 360 brass or free-cutting brass — is the standard North American free-machining brass per ASTM B16, with 60–63% copper and 2.5–3.7% lead. It is the alloy against which copper-alloy machinability is rated (100%), and the default choice for high-speed screw-machined parts such as fittings, connectors, fastener components, and sensor bodies.

What is the EN (CW) equivalent of C36000?

The closest EN composition match is CW603N (CuZn36Pb3). In commercial cross-reference tables C36000 is also very commonly matched to CW614N (CuZn39Pb3), the standard European free-machining grade, which behaves near-identically in machining. The legacy British designation is CZ124, and JIS C3604 is a close Japanese equivalent.

Is C36000 RoHS compliant and safe for drinking water?

C36000 relies on RoHS Annex III Exemption 6(c), which permits up to 4% lead in copper alloys (currently valid to 30 June 2027). It is not suitable for wetted parts in US potable-water systems, where NSF/ANSI 372 limits weighted lead content to 0.25% — specify a lead-free grade such as CW724R or C6802 instead.

Can Brassland machine C36000 parts?

Yes — parts are machined to your drawing and specification. Depending on bar availability we machine C36000 or the equivalent EN free-machining grades CW614N/CW603N; the exact grade and a Type 3.1 mill certificate (EN 10204) are confirmed at quotation. Send your drawing for a quote within 24 hours.

C36000 screw-machined in Jamnagar

The US benchmark free-cutting brass, made to your drawing. ISO 9001:2015. Quote within 24 hours.

Request a Quote
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 C36000 alloy datasheet — composition & properties
ASTM B16/B16M
Free-Cutting Brass Rod, Bar and Shapes for Screw Machines
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.