MEI 70
Overview
MEI-70 (Cartridge Brass) offers excellent cold forming with outstanding ductility, good hot forming properties and excellent soldering and brazing
characteristics. The benchmark alloy for deep drawing, ammunition and precision stamping applications.
| CHEMICAL COMPOSITION (wt. %) | ALLOY DESIGNATIONS | COIL / SHEET SPECIFICATIONS | |||
|---|---|---|---|---|---|
| Element | Composition (%) | Standard | Designation | Specification | Range |
| Cu | 69.00 – 71.00 | IS | IS 410 | Thickness (mm) | 0.04 – 3.0 |
| Fe | ≤0.05 | JIS | C2600 | Width (mm) | 6.00 – 406 |
| Pb | ≤0.05 | ISO | CuZn30 | Inner Dia. (mm) | 100/150/200/300 0/400/500 |
| Ni | ≤0.10 | ASTM | C26000 | Coil Wt. (kg/mm) | 1.0 – 4.0 |
| Zn | Rem. | BS | CZ106 | Sheet Length (m) | 0.50 – 4.00 |
| MECHANICAL PROPERTIES — typical values at 20°C | ||||||
|---|---|---|---|---|---|---|
| Temper | Code | HV | Tensile MPa | Yield MPa | Elong. % | Grain Size mm |
| Annealed | O | 55–75 | 275–330 | ≤160 | ≥45 | 0.035–0.100 |
| 1/4 Hard | H01 | 75–90 | 330–370 | ≥180 | ≥40 | 0.015–0.050 |
| 1/2 Hard | H02 | 95–125 | 380–440 | ≥220 | ≥30 | ≤0.015 |
| 3/4 Hard | H03 | 125–145 | 440–480 | ≥360 | ≥15 | ≤0.010 |
| Hard | H04 | 140–160 | 480–540 | ≥410 | ≥10 | ≤0.010 |
| Extra Hard | H06 | 160–180 | 540–610 | ≥450 | ≥5 | ≤0.005 |
| Spring Hard | H08 | ≥180 | ≥610 | ≥530 | — | ≤0.005 |
| PHYSICAL PROPERTIES — annealed temper at 20°C | ||||
|---|---|---|---|---|
| Density (g/cm³) | Elec. Conductivity (% IACS) | Thermal Conductivity (W/m·K) | Modulus of Elasticity (GPa) | Specific Heat (J/kg·K) |
| 8.53 | 28 | 126 | 115 | 377 |
| FABRICATION PROPERTIES | |||
|---|---|---|---|
| Fabrication Property | Rating | Fabrication Property | Rating |
| Capacity for Cold Working | Excellent | Soft Soldering | Excellent |
| Machinability | Less suitable | Resistance Welding | Good |
| Electroplating | Excellent | Gas Shielded Arc Welding | Fair |
| Hot Dip Tinning | Excellent | Laser Welding | Less suitable |
| CORROSION RESISTANCE |
|---|
|
MEI-70 has very good resistance to water, water vapor, different saline solutions, many organic liquids and industrial atmosphere. Under cold formed temper this alloy may tend to stress corrosion cracking with hydrous ammonia environment; heat treatment can effectively prevent this.
|
| TYPICAL APPLICATIONS | |
|---|---|
| • Terminal connectors, flashlight shells, lamp fixtures | • Odometer contacts, heater cores, thermostats, radiator cores and tanks |
| • Ammunition cartridge cases and mechanical housing | • Jewelry and metal goods |