GRP Grades & Mechanical Performance
We manufacture our fibreglass profiles in strict compliance with BS EN 13706, the European standard that defines the performance of pultruded GRP products. This standard is critical when selecting profiles for load-bearing and structural applications, where strength, stiffness, and long-term safety are essential.
What Are GRP Grades?
GRP grades refer to the mechanical performance classification of pultruded profiles. Under BS EN 13706 there are two principal grades:
- E17 – Standard structural grade
- E23 – Enhanced structural grade
The difference between them lies in their minimum mechanical properties, such as tensile strength, flexural strength, and modulus. These values determine how a profile behaves under load and ensure that it is suitable for demanding structural uses.
Our standard:
All GRP profiles with a wall thickness greater than 5 mm are manufactured to E23 grade as standard, providing a higher level of performance and safety margin for most applications.
GRP Compliance To Industry Standards
The table below outlines the minimum mechanical properties required for each grade under BS EN 13706
| Units | Property Data | ||
| E23 Grade | E17 Grade | ||
| Full section modulus | GPa | 23 | 17 |
| Tensile strength (axial) | MPa | 240 | 170 |
| Tensile strength (transverse) | MPa | 50 | 30 |
| Tensile Modulus (axial) | GPa | 23 | 17 |
| Tensile Modulus (transverse) | GPa | 7 | 5 |
| Flexural strength (axial) | MPa | 240 | 170 |
| Flexural strength (transverse) | MPa | 100 | 70 |
| Inter-laminar shear | MPa | 25 | 15 |
| Pin bearing strength | MPa | 70 | 50 |
GRP Grades – FAQs
E17 and E23 are mechanical performance grades defined in BS EN 13706. E23 offers higher tensile and flexural strength and higher modulus values than E17, making it better suited to heavy-duty or safety-critical structural applications.
E23 is recommended wherever profiles are load-bearing, exposed to high traffic, or used in areas where deflection and long-term performance are critical – for example walkways, platforms, access gantries and support frames.
Any profile we produce with a wall thickness greater than 5 mm is manufactured to E23 grade as standard, giving you enhanced performance without needing to request an upgrade.
The grade mainly relates to mechanical properties, not corrosion resistance. Both E17 and E23 use high-quality resins and glass fibres that provide excellent resistance to chemicals, weathering and moisture.
Start with your loading data—span, point loads, uniform loads and deflection limits. Share this information with our technical team and we’ll help you select the correct grade and profile to satisfy BS EN 13706 and your project’s safety factors.
Need Help Specifying GRP Grades?
Whether you’re upgrading existing infrastructure or designing a new structure, we can advise on the correct GRP grade, profile size and span.