Conductivity. Dielectric.
Magnetic. Thermal.
Electrical material data.
Electrical properties reference. Conductivity, dielectric strength, breakdown voltage, magnetic permeability. Material data for engineering.
Key principles.
σ in S/m
Reciprocal of resistivity. Copper 5.96×10⁷ S/m.
ρ in Ω·m
Material resistance. Silver 1.6×10⁻⁸ Ω·m.
εr
Capacitance increase factor. Air 1, water 80.
kV/mm
Insulation failure voltage. Air 3 kV/mm, glass 30+ kV/mm.
µr
Magnetic susceptibility. Iron 5000, aluminum 1, copper 1.
Tracking resistance
Comparative Tracking Index. Higher = better.
FAQ
Conductivity vs resistivity?
Reciprocals. σ = 1/ρ. Both express same property.
Dielectric strength temperature?
Generally decreases with temperature. Specify per service condition.
Permeability importance?
Magnetic field design. Iron strongly affects. Aluminum/copper minimal.
Specifying electrical materials?
Per relevant property: conductor (low ρ), insulator (high breakdown), magnetic (high µ).
Testing methods?
ASTM D257 resistivity, ASTM D149 dielectric strength, ASTM E1300 permeability.
Material data sources?
Manufacturer datasheets standard. ASM Handbook comprehensive. NIST for primary research.