Technical metallurgical reference database comparing 15 free-machining, forging, DZR, and lead-free brass alloys (CW614N, CZ121, C36000, IS 319, CW617N, C69300 Eco-Brass).
Brass alloys are copper-zinc binary or multi-element solid solutions engineered for specific mechanical, corrosion, and machining characteristics. Free-machining brasses incorporate lead (Pb) to form micro-globules that act as internal chip breakers and lubricants during high-speed automatic lathe and Swiss CNC turning operations. Forging brasses balance copper and zinc to optimize hot plastic deformation without cracking, while silicon (Si) and arsenic (As) alloy additions prevent dezincification (DZR) in aggressive aqueous environments.
At Divine Brass Industries, our in-house optical emission spectro laboratory performs 100% heat-code chemical verification on all incoming extruded brass rod stock, guaranteeing compliance with European (EN 12164 / EN 12165), American (UNS / ASTM B16 / ASTM B124), British (BS 2874), and Indian (IS 319 / IS 3488) standards.
| European (EN 12164 / 12165) | United States (UNS / ASTM) | British (BS Standards) | Indian (IS Standards) | Japanese (JIS Standards) | Machinability Index | Primary Industrial OEM Usage |
|---|---|---|---|---|---|---|
| CuZn39Pb3 (CW614N) | C36000 (Free Cutting) | CZ121 (Pb 3%) | IS 319 Grade I | C3604 | 100% (Standard) | Swiss CNC turned parts, threaded inserts, connector pins, precision fasteners. |
| CuZn40Pb2 (CW617N) | C37700 (Forging Brass) | CZ122 | IS 3488 | C3771 | 80% | Hot closed-die forged valve bodies, pressure fittings, hydraulic manifolds. |
| CuZn36Pb3 (CW603N) | C36000 (High Lead) | CZ124 | IS 319 Grade II | C3602 | 95% | Complex knurled inserts, electrical neutral links, terminal block screws. |
| CuZn31Si1 (CW708R / DZR) | C69300 (Eco-Brass) | CZ132 (Dezincification) | IS 836 DZR | C6801 | 80% | Potable drinking water valves, plumbing fittings, marine hardware (Pb ≤ 0.09%). |
| CuZn37 (CW508L) | C27200 (Yellow Brass) | CZ108 | IS 407 | C2700 | 30% (Cold Form) | Deep drawing, stamping, electrical rivets, cold-headed components. |
| CuZn39Pb2 (CW612N) | C37700 | CZ131 | IS 319 Grade III | C3710 | 90% | Combined closed-die hot forging & secondary high-speed CNC finish machining. |
| CuZn40Pb2Al (CW618N) | C67500 (Manganese Bronze) | CZ114 | IS 291 | C6782 | 50% | Heavy-duty bushings, wear plates, high-strength marine shafting. |
| Alloy Designation | Copper (Cu) % | Lead (Pb) % | Iron (Fe) % | Tin (Sn) % | Aluminum (Al) % | Silicon (Si) % | Zinc (Zn) % |
|---|---|---|---|---|---|---|---|
| CW614N / CZ121 | 57.0 – 59.0% | 2.5 – 3.5% | ≤ 0.30% | ≤ 0.30% | ≤ 0.05% | ≤ 0.05% | Balance |
| C36000 (UNS) | 60.0 – 63.0% | 2.5 – 3.7% | ≤ 0.35% | ≤ 0.30% | ≤ 0.05% | ≤ 0.05% | Balance |
| CW617N (Forging) | 57.0 – 59.0% | 1.6 – 2.5% | ≤ 0.30% | ≤ 0.30% | ≤ 0.05% | ≤ 0.05% | Balance |
| CW708R (DZR Lead-Free) | 73.0 – 77.0% | ≤ 0.09% | ≤ 0.10% | ≤ 0.10% | ≤ 0.05% | 2.7 – 3.4% | Balance |
| CW508L (CW37) | 62.0 – 64.0% | ≤ 0.10% | ≤ 0.10% | ≤ 0.10% | ≤ 0.05% | ≤ 0.05% | Balance |
| Alloy Grade | Tensile Strength Rm (MPa) | Yield Strength Rp0.2 (MPa) | Hardness (HB 10/1000) | Elongation A5 (%) | Shear Strength (MPa) |
|---|---|---|---|---|---|
| CW614N / CZ121 | 360 – 500 MPa | 220 – 350 MPa | 110 – 160 HB | 10 – 20% | 230 MPa |
| CW617N (Forged) | 400 – 520 MPa | 250 – 380 MPa | 120 – 170 HB | 12 – 25% | 260 MPa |
| CW708R (Eco-Brass) | 450 – 580 MPa | 280 – 400 MPa | 130 – 180 HB | 15 – 30% | 310 MPa |
| Alloy Grade | Density (g/cm³) | Melting Point (°C) | Thermal Conductivity (W/m·K) | Electrical Conductivity (% IACS) | Modulus of Elasticity (GPa) |
|---|---|---|---|---|---|
| CW614N / CZ121 | 8.44 g/cm³ | 885 – 900 °C | 115 W/m·K | 28% IACS | 105 GPa |
| CW617N (Forged) | 8.41 g/cm³ | 880 – 895 °C | 110 W/m·K | 27% IACS | 100 GPa |
| CW708R (Eco-Brass) | 8.25 g/cm³ | 860 – 890 °C | 35 W/m·K | 7% IACS | 110 GPa |
Under EU RoHS 3 Directive 2015/863/EU (Exemption 6c), lead content up to 4.0% by weight is authorized for copper alloys used in electrical equipment and industrial machinery. For drinking water systems, California Proposition 65 and NSF/ANSI 61 demand lead-free Eco-Brass (≤ 0.09% Pb).
