CuZn39Pb3 is the workhorse free-machining brass of the precision engineering world — a leaded alpha-beta brass prized for outstanding machinability, excellent hot formability and reliable strength. Under the European standard it carries the numeric designation CW614N, and it is the single most widely turned, forged and stamped brass grade in the world. This guide covers its full chemistry, mechanical and physical properties, standard sizes, typical components and the industries it serves — plus a built-in round & hex bar weight calculator. We offer Brass CuZn39Pb3 Nuts, Brass CuZn39Pb3 CNC machined parts, Brass CuZn39Pb3 Turned parts, Brass CuZn39Pb3 bushes, Brass CuZn39Pb3 Swiss machined parts, Brass CW614N Pins, Brass CuZn39Pb3 Transformer spade terminals, Brass CuZn39Pb3 threaded fittings etc.
CuZn39Pb3 (CW614N) — round & hexagonal free-machining brass rod
Bright-drawn CuZn39Pb3 round and hexagonal brass rod — the standard feedstock for CNC turning and hot stamping.
What Is CuZn39Pb3 Brass?
CuZn39Pb3 is a leaded (dezincification-tolerant) alpha-beta brass containing roughly 58% copper, 39% zinc and 3% lead. The finely dispersed lead particles act as internal chip-breakers and lubricant, giving the alloy a machinability rating of 100% — the very benchmark against which every other copper alloy is rated. The dual-phase (α+β) microstructure also makes it exceptionally easy to hot forge and stamp at 650–750 °C. It is known by several names across standards: EN designation CW614N, material number CuZn39Pb3, US equivalent C36000 (free-cutting brass), and legacy UK grade CZ121. For the application-focused view of the same metal, see our companion guide on CW614N brass.
Chemical Composition
CuZn39Pb3 / CW614N chemical composition per EN 12164
Element
Symbol
Content (%)
Copper
Cu
57.0 – 59.0
Lead
Pb
2.5 – 3.5
Iron (max)
Fe
0.30
Nickel (max)
Ni
0.30
Aluminium (max)
Al
0.05
Tin (max)
Sn
0.30
Zinc
Zn
Balance (≈38.5)
Mechanical Properties
Typical mechanical properties (rod, EN 12164, temper R360)
Property
Value
Unit
Tensile strength (Rm)
360 – 470
MPa
0.2% proof stress (Rp0.2)
≥ 130
MPa
Elongation at fracture (A)
≥ 15
%
Hardness
90 – 110
HB
Machinability rating
100 (benchmark)
%
Higher tempers such as R430 raise tensile strength to 430–530 MPa through cold drawing. The alloy is not hardenable by heat treatment — strength is set by the degree of cold work.
Physical Properties
CuZn39Pb3 physical properties at 20 °C
Property
Value
Unit
Density
8.47
g/cm³
Melting range
875 – 895
°C
Modulus of elasticity
≈ 97
GPa
Thermal conductivity
≈ 117
W/(m·K)
Coefficient of thermal expansion (20–300 °C)
21.4
×10⁻⁶/K
Electrical conductivity
≈ 25
% IACS
Machinability & Fabrication
The defining feature of CuZn39Pb3 is its machining behaviour. On high-speed CNC lathes and multi-spindle Swiss-type machines it produces short, easily evacuated chips, allows aggressive feeds and speeds, and delivers superb surface finishes with long tool life. It also responds well to hot forging, hot stamping, sawing, drilling, tapping, knurling and roll threading, and can be readily nickel- or chrome-plated for decorative and corrosion-resistant finishes.
Precision CNC-turned CuZn39Pb3 components — gland bodies, threaded inserts & fittings
Typical precision-machined CuZn39Pb3 parts: cable-gland bodies, threaded inserts and stepped hose fittings.
Typical Sizes & Product Forms
Conex supplies CuZn39Pb3 in a full range of drawn, extruded and forged forms. Common stock dimensions:
Standard CuZn39Pb3 product forms & size ranges
Form
Size range
Standard
Round rod / bar
2 – 120 mm dia
EN 12164 / EN 12163
Hexagonal rod (across flats)
3 – 80 mm A/F
EN 12164
Square rod
3 – 60 mm
EN 12164
Hollow rod / tube
Custom bore
EN 12164
Forging stock & profiles
To drawing
EN 12165
Wire
1 – 12 mm
EN 12166
Common Parts Manufactured from CuZn39Pb3
Cable glands & entry components
Threaded inserts & standoffs
Hose & pneumatic fittings
Terminal blocks & connectors
Valve & tap bodies
Sanitary & plumbing fittings
Automotive sensor housings
Fasteners, nuts & screws
Gas & water meter parts
Electrical accessories
Decorative hardware
Precision turned inserts
Industries Served
Electrical & power distribution
Plumbing & sanitary ware
Automotive & EV
Oil, gas & hydraulics
Instrumentation & sensors
Telecommunications
HVAC & refrigeration
Building & construction hardware
Renewable energy
CuZn39Pb3 Weight Calculator — Round & Hex Bars
Enter a diameter (for round bar) or across-flats size (for hexagonal bar) and a length to estimate the weight of CuZn39Pb3 / CW614N based on a density of 8.47 g/cm³.
Brass Bar Weight Calculator
Weight per piece: —
Weight per metre: —
Total weight: —
Indicative only. Based on CuZn39Pb3 (CW614N) density 8.47 g/cm³ (8470 kg/m³). Round: area = π/4 × d². Hex: area = (√3/2) × A/F². Actual weights vary with tolerance and exact alloy composition.
Quick reference — weight per metre (kg/m)
CuZn39Pb3 theoretical weight per metre (density 8.47 g/cm³)
Size (mm)
Round bar (kg/m)
Hex bar A/F (kg/m)
6
0.239
0.264
8
0.426
0.470
10
0.665
0.734
12
0.958
1.057
16
1.703
1.879
19
2.402
2.649
20
2.661
2.936
25
4.157
4.587
30
5.987
6.606
36
8.621
9.512
40
10.643
11.744
50
16.629
18.350
International Equivalents
CuZn39Pb3 cross-reference across standards
Standard / Region
Designation
EN (Europe) — number
CW614N
EN / ISO — name
CuZn39Pb3
USA (ASTM/UNS)
C36000 (Free-Cutting Brass)
UK (legacy BS)
CZ121
Germany (old DIN)
2.0401
Need CuZn39Pb3 / CW614N Components?
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