Properties of pultruded shapes

Glass content of 40 à 80 % by weight

Mechanical properties

Density 1.6 to 2.10
Barcol Hardness 40 to 55

Mechanical properties

Flexural modulus (MPa) 17000 to 40 000
Ultimate tensile stress (MPa) 250 to 700
Tension failure elongation (%) 1.5 to 2
Ultimate bending stress (MPa) 250 to 700
Ultimate compressive stress (MPa) 200 to 450

The values indicated correspond to the longitudinal properties of the filed sections.

Physical properties

The GDP profiles are in accordance with EN 13 706 - 2 & 3 European Standard

Dielectric properties

Dielectric constant (KV/mm): 6 to 12
Specific resistance (Ohm/mètre) 1012

Thermal properties

The standard pultruded shapes can be used without any restriction between -20 °C and +80 °C. It is possible to use them in harsh conditions below -20 °C and between +80 °C / +200 °C, in these cases, special formulations are required.

Coefficient of thermal expansion (10-6 * K-1) 8 to 10
Thermal endurance class : PR500 - class “B” (130 °C)
& PR100 - class “H” (180 °C)


1/ Flame resistance

  PR400 PR500
Limited Oxygen Index
(NFT 51 071)
Axial :
80 to 90 %
Transverse :
50 to 60 %
Axial :
30 to 35 %
Transverse :
25 to 30 %
Resistance to incandescent
filament during 30 seconds
at 960 °C
(NFT 20 455 20 455)
No flaming
when filament
is applied
Extinction time
less than
5 seconds

2/ Flame and smoke specifications can be attained
with specific formulations

  Normes Classe
France NFF 16 101
NFP 92 057
U.S.A. UL 94 V0
Germany DIN 4102 B1
United Kingdom BS 476 Part 7 Class 1

3/ Resistance to chemicals agents

  PR400 PR500 PR600      
Resistance to acids oo oo ooo      
Resistance to bases o o oo      
Organic solvents - - o      
Chlorinated solvents - - o      
Sea water oo oo ooo   - Not recommended
Petrol/Diesel oil oo oo ooo   o Resistant
Industrial detergents ooo ooo ooo   oo Very resistant
Weathering ooo ooo ooo   ooo

Excellent resistant


Behaviour of GDP composites profiled sections


As regards to elasticity, the profiled sections have linear behaviour, as shown by the typical elasticity graph above. Therefore they are perfectly suitable for applications that involve either cyclical mechanical stresses or vibrations either repeated impacts.   The normal graph above shows characteristics of dynamic 3 points bending of glass fibers profiled sections: 10% decrease in modulus after 500 000 cycles under imposed elongation at 80% ultimate stress, with a frequency of 10 Hz -This decrease in stiffness is very slight.
Very little fatigue is observed in the material.


Using GDP composites profiled sections
- Cutting and machining

The profiled sections can be worked with conventional machining methods or cut with water jets – For your safety and convenience, we recommend that you use masks, safety glasses and protective to avoid irritation by glass dust.


The best results are obtained with a low feed rate and low machining pressure. Spray with water is recommended to cool the machining area and limit dust propagation. If water cannot be used, dry machining is possible. 


Use diamond blades with a circumference speed between 40 and 60 Meter/Second.
A metal cutting saw can be used as a temporary substitute or for small quantities.


Standard or carbide-tipped drill bits will have a short lifetime. For large quantities, use diamond impregnated bell milling cutters.


Standard tools for small and medium quantities can be used. For large quantities, use tools with cemented carbide tips or diamond tips.


Suitable for thin profiled sections.

- Protection of profiled sections

After machining and drilling of the profiles, a varnish or resin can be used to protect the material, particularly in very corrosive environments or in water treatments.

- Assemblying and bonding

Standard assembly techniques with bolts may be used. Ideally, composite material bolt or stainless steel bolt should be used.

For heavily loaded assemblies with shear stress, pulling or vibration, it is recommended to bond the profiles.

• Bonding is highly efficient if the surface is well prepared by sanding and removing dust and grease.

• Polyurethane, epoxy or acrylic glues are suitable. GDP technical office is ready to help you solving any machining and cutting problems. GDP machining shop is able to delivered any machined profile.