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General Unsaturated polyester (UP+GF15+MD60), Type 804

Alternative and trade names
Bakelite®, Melopas®


Reinforced with 15% Glass Fibres and filled with 60% Mineral Powder.



Dielectric constant εr

3 - 7 [-] at 20 °C

Electrical resistivity ρel

1.00E+1 - 1.00E+12 Ω·m at 20 °C


Density ρ

1.98 - 2.28 g/cm³ at 20 °C


Elastic modulus E

11 - 13 GPa at 20 °C

Elongation A

0.6 - 1.2 % at 20 °C

Impact strength, Charpy notched Ivnot

2.4 - 7 kJ/m² at 20 °C

Impact strength, Charpy unnotched Iunnot

5 - 13 kJ/m² at 20 °C

Max allowed stress σmax

45 - 65 MPa at 20 °C

at 0.6-1.2% strain





Coefficient of thermal expansion α

1.5E-5 - 4E-5 1/K at 20 °C


UL 94 V1-V0

Max service temperature, long Tmaxlong

170 °C

Max service temperature, short Tmaxshort

210 °C

Specific heat capacity cp

1200 J/(kg·K) at 20 °C

Thermal conductivity λ

0.6 - 0.8 W/(m·K) at 20 °C

Technological properties

Application areas

explosion proof switches, safety switch housings, oven knobs, lamp parts

Processing methods

Injection molding, transfer molding, compression molding

This material data has been provided by M-Base.

All metrics apply to room temperature unless otherwise stated. SI units used unless otherwise stated.
Equivalent standards are similar to one or more standards provided by the supplier. Some equivalent standards may be stricter whereas others may be outside the bounds of the original standard.