Leaded Free-Machining Brass — US Benchmark Grade

C36000 Free-Cutting Brass

Free-Cutting Brass 360 — CuZn36Pb3 / ASTM B16

C36000 (free-cutting brass 360, CuZn36Pb3, ASTM B16) is the North American free-machining brass that defines the copper-alloy machinability scale at 100%, with 60–63% copper and 2.5–3.7% lead; its EN equivalent is CW603N (legacy BS CZ124). 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 — bismuth brass, ~90% 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.

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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 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.

Made by Brassland
Need parts in C36000?

Brassland machines C36000 into brass turned parts and CNC machined components to your drawing in Jamnagar, India, including precision turned brass components on 28+ Swiss-type lathes, with an EN 10204 3.1 certificate on every shipment.

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