Structural Lead-Free — Hot Forging

CW510L

CuZn42 — EN 12167 / EN 12165

The highest-zinc lead-free brass — built for hot forging, extrusion and pressing where no lead is permitted. 42% Zn puts it deep in the α+β region for outstanding hot workability; machinability is ~48%. RoHS compliant with no exemption.

🔥 Excellent Hot Forging
🌿 Lead-Free — RoHS
📋 EN 12167 / 12165
⚙️ ~48% Machinability
🌍 CuZn42
~42%
Zinc — deepest into the β region
650–800°C
Hot forging window
~48%
Machinability vs benchmark
RoHS ✓
No exemption required
Chemical Composition

CW510L — EN 12167 Limits

Weight %. Maximum zinc for maximum hot-forming economy — without lead.

ElementSymbolMin %Max %Typical %
CopperCu57.059.058.0
ZincZnBalance~42
Lead (max) ✓Pb0.10≤0.05
IronFe0.300.05
Copper (Cu)
~58%
Zinc (Zn)
~42%
Lead ✓
≤0.05%
Mechanical Properties

Typical (annealed)

PropertyConditionValueUnit
Tensile Strength (Rm)annealed380–440MPa
Proof Stress (Rp0.2)annealed≥150MPa
Elongation (A)annealed≥25%
Hardnessannealed90–115HB
Hot Forging Temp650–800°C
Machinabilityvs C36000 = 100~48%
Density8.37g/cm³
Melting Rangesolidus–liquidus890–900°C
Typical Applications
  • Lead-free hot-forged fitting and component blanks
  • Hot-pressed and extruded structural parts
  • Regulated-market components where no Pb addition is allowed
  • Forged blanks finish-machined to drawing
Why choose CW510L?

Lead-free forging economics

  • Outstanding hot workability — fills dies at 650–800°C nearly as well as leaded forging brass
  • Lead-free by composition — RoHS compliant, future-proof against Exemption 6(c) changes
  • Economical — cheaper than silicon brass when DZR is not required
  • ~48% machinability — plan finish-machining allowances; forming is this alloy's strength
  • Not DZR — for potable wetted parts specify CW724R/C69300 instead
RoHS & Compliance

Compliance Status

RoHS
✓ Fully Compliant
Lead-free by composition — no exemption needed.
Drinking Water
Not DZR-Qualified
Low lead helps compliance, but dezincification resistance is not certified — for wetted potable parts use a silicon brass.
Leaded forging alternative
CW617N / C37700 — where Ex 6(c) is acceptable
International Equivalents

CW510L Cross-Reference

StandardDesignation
EN (Europe)CW510L / CuZn42
ASTM (USA)C28000 (close)
BS (UK legacy)CZ110 (close)
DIN (Germany)CuZn42
ISOCuZn42
There is no exact UNS twin for CuZn42 — US lead-free forging specs usually land on C46400 or proprietary low-lead grades. Confirm composition limits when substituting.
← Leaded forging
CW617N
CuZn40Pb2 — the Ex 6(c) workhorse
Extrusion cousin →
CuZn40
Muntz metal — 60/40 duplex
↑ All alloys
Materials Library
Frequently Asked Questions

CW510L — common questions

What is CW510L brass used for?

CW510L (CuZn42) is a high-zinc, lead-free brass specified in EN 12167 whose duplex structure gives outstanding workability at forging temperature. It is used for hot-forged and extruded structural components where the part must contain no added lead.

Is CW510L RoHS compliant?

Yes — CW510L is lead-free by composition, so it is RoHS compliant without relying on Exemption 6(c), and is unaffected by the exemption's expected tightening after June 2027.

How does CW510L machine compared with leaded brass?

It rates around 48% machinability — roughly half the cutting performance of CW614N — with tougher, longer chips. Plan finish-machining allowances accordingly; the alloy's strength is in hot forming, with machining as a secondary operation.

When should I pick CW510L over CW724R for lead-free work?

Choose CW510L for hot-forged or extruded structural parts where cost matters and dezincification resistance is not required. Choose CW724R silicon brass when the part is wetted by potable water or needs DZR performance plus better machinability.

CW510L forged & machined in Jamnagar

Lead-free forgings, finish-machined 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 alloy database — 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.