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Documentation - Pultruded Shapes - Technical Data

Pultruded Shapes Technical Data

Representative Material Properties for ISO and VE Pultruded FRP

Technical Overview

The following tables provide representative mechanical, physical, thermal, and electrical properties for Fiberr pultruded fiberglass-reinforced plastic profiles manufactured with isophthalic polyester (ISO) and vinyl ester (VE) resin systems.

Pultruded FRP is an anisotropic composite material. Its properties differ by direction because continuous fiberglass rovings provide most of the reinforcement along the length of the profile, while woven reinforcement, chopped strand mat, transverse fibers, and resin provide strength across the profile.

Isophthalic Polyester (ISO) A general-purpose structural resin system offering a balance of mechanical performance, corrosion resistance, availability, and cost for common industrial and commercial applications.
Vinyl Ester (VE) A higher-performance resin system offering increased mechanical properties and improved resistance to aggressive chemicals, moisture, and corrosive service environments.
Directional terminology: Axial or longitudinal properties are measured parallel to the direction in which the profile is pultruded. Transverse properties are measured perpendicular to the pultrusion direction. The appropriate directional value should be used for the expected load path.

Mechanical, Physical & Thermal Properties

Representative Pultruded FRP Material Properties

Property Standard Imperial Units Metric Units Typical Low-Carbon Mild Steel Comparison
ISO VE Units ISO VE Units
24-Hour Water Absorption ASTM D570 0.3 0.3 % 0.3 0.3 % Not applicable to metal; ASTM D570 is a plastics and composites water-absorption test.
Barcol Hardness ASTM D2583 45 45 Barcol 45 45 Barcol Rockwell B80 typical; Barcol hardness is not normally used for steel.
Bearing Stress Axial ASTM D953 44 50.7 ksi 305 349 MPa Steel bearing allowables depend on joint geometry, fastener arrangement, material grade, and applicable design code.
Bearing Stress Transverse ASTM D953 38 43.8 ksi 265 302 MPa Steel bearing allowables depend on joint geometry, fastener arrangement, material grade, and applicable design code.
Coefficient of Thermal Expansion Longitudinal ASTM D696 7 × 10−6 7 × 10−6 in/in-°F 12.6 × 10−6 12.6 × 10−6 mm/mm-°C Approximately 5.61–9.22 × 10−6 in/in-°F or 10.1–16.6 × 10−6 mm/mm-°C.
Coefficient of Thermal Expansion Transverse ASTM D696 16 × 10−6 16 × 10−6 in/in-°F 28.8 × 10−6 28.8 × 10−6 mm/mm-°C Steel is substantially isotropic, with similar thermal expansion in each direction.
Compressive Modulus Axial ASTM D695 2,625 2,625 ksi 18.1 18.1 GPa Approximately 29,700 ksi or 205 GPa.
Compressive Modulus Transverse ASTM D695 1,030 1,236 ksi 7.1 8.5 GPa Approximately 29,700 ksi or 205 GPa in all directions.
Compressive Shear Stress ASTM D3846 3.8 4.1 ksi 26 29 MPa Steel shear strength varies by material grade and condition.
Compressive Strength Axial ASTM D695 46 52.3 ksi 320 361 MPa Approximate compressive yield comparable to tensile yield: 55.8 ksi or 385 MPa.
Compressive Strength Transverse ASTM D695 16 19.4 ksi 112 134 MPa Approximately 55.8 ksi or 385 MPa in all directions.
Flexural Modulus Axial ASTM D790 3,408 4,260 ksi 23.5 29.4 GPa Approximately 29,700 ksi or 205 GPa.
Flexural Modulus Transverse ASTM D790 1,073 1,341 ksi 7.4 9.2 GPa Approximately 29,700 ksi or 205 GPa in all directions.
Flexural Strength Axial ASTM D790 35 39.8 ksi 240 274 MPa Approximately 55.8 ksi yield and 76.9 ksi ultimate, or 385 MPa yield and 530 MPa ultimate.
Flexural Strength Transverse ASTM D790 15 17 ksi 100 118 MPa Steel is substantially isotropic; strength depends on grade and yield criteria.
Heat Deflection Temperature ASTM D648 302 356 °F 150 180 °C Not normally applied to steel; HDT is a plastics and composites property.
Interlaminar Shear Strength ASTM D2344 3.6 4.1 ksi 25 28 MPa Not applicable because steel is not a laminated composite.
Maximum Recommended Continuous Service Temperature — 150 200 °F 66 93 °C Steel service temperature depends on grade, coating, oxidation, loading, and design criteria.
Notched Izod Impact Strength ASTM D256 25.7 30.8 ft-lb/in 1.40 1.68 kgf·m/cm Steel impact values are normally reported using different specimen and test conventions.
Pin Bearing Strength Axial ASTM D953 22 25.3 ksi 150 175 MPa Steel pin-bearing capacity depends on pin diameter, hole geometry, edge distance, thickness, and design code.
Pin Bearing Strength Transverse ASTM D953 10 11.5 ksi 70 79 MPa Steel pin-bearing capacity depends on connection geometry and design criteria.
Poisson’s Ratio, Longitudinal ASTM D3039 0.35 0.35 — 0.35 0.35 — Approximately 0.29.
Shear Modulus ASTM D5379 420 420 ksi 2,895 2,895 MPa Approximately 11,500 ksi or 79 GPa.
Specific Gravity / Relative Density ASTM D792 1.66–1.93 1.66–1.93 — 1.66–1.93 1.66–1.93 — Approximately 7.85 specific gravity, 7.85 g/cm³, or 0.284 lb/in³.
Tensile Modulus / Young’s Modulus Axial ASTM D638 3,335 4,002 ksi 23.0 27.6 GPa Approximately 29,700 ksi or 205 GPa.
Tensile Modulus / Young’s Modulus Transverse ASTM D638 1,015 1,269 ksi 7.0 8.7 GPa Approximately 29,700 ksi or 205 GPa in all directions.
Tensile Strength Axial ASTM D638 35 39.8 ksi 240 274 MPa Approximately 55.8 ksi yield and 76.9 ksi ultimate, or 385 MPa yield and 530 MPa ultimate.
Tensile Strength Transverse ASTM D638 7.25 7.7 ksi 50 53 MPa Steel is substantially isotropic; approximately 55.8 ksi yield and 76.9 ksi ultimate.
Thermal Conductivity ASTM C177 4.0 4.0 BTU-in/ft²-hr-°F 0.58 0.58 W/m-K Approximately 175–645 BTU-in/ft²-hr-°F or 25.3–93.0 W/m-K, depending on grade and temperature.
Steel comparison: The steel values are included only to provide general context. FRP and steel behave differently and should not be selected by comparing a single material property. Structural design must consider stiffness, strength, anisotropy, buckling, connection behavior, creep, corrosion, weight, electrical conductivity, thermal conductivity, temperature, and applicable design criteria.

Electrical Properties

Representative Electrical and Insulation Properties

Property Standard Imperial Units Metric Units Typical Low-Carbon Mild Steel Comparison
ISO VE Units ISO VE Units
Arc Resistance ASTM D495 80 80 s 120 120 s Not applicable; steel is electrically conductive.
Dielectric Constant / Relative Permittivity ASTM D150 ≤5 5.2 — ≤5 5.2 — Not applicable; steel is not a dielectric insulating material.
Dielectric Strength Axial ASTM D149 246.3 246.3 kV/in 9.7 9.7 kV/mm Not applicable; steel is electrically conductive.
Dielectric Strength Transverse ASTM D149 264.7 264.7 kV/in 10.42 10.42 kV/mm Not applicable; steel is electrically conductive.
Dissipation Factor, 60 Hz ASTM D150 0.03 0.03 — 0.03 0.03 — Not applicable; steel is not a dielectric insulating material.
Surface Resistance ASTM D257 1 × 1010–1 × 1015 1 × 1010–1 × 1015 Ω 1 × 1010–1 × 1015 1 × 1010–1 × 1015 Ω Not applicable as an insulation property; measured resistance depends on geometry, finish, oxide condition, and contact method.
Volume Resistivity / Specific Insulation Resistance ASTM D257 3.94 × 1012 >3.94 × 1013 Ω·in 1.00 × 1013 >1.00 × 1014 Ω·cm Typical steel electrical resistivity is approximately 5.63 × 10−6 Ω·in or 1.43 × 10−5 Ω·cm.
General guidance only: Values shown are representative of standard test specimens prepared, conditioned, and tested under the applicable ASTM methods. Actual product properties may vary with profile geometry, wall thickness, overall dimensions, resin formulation, fiberglass content, roving configuration, woven reinforcement, chopped strand mat, surface veil, number and placement of reinforcement layers, pigments, fillers, fire-retardant additives, UV stabilizers, cure conditions, manufacturing tolerances, test direction, specimen preparation, temperature, moisture, and environmental exposure. These values are not guaranteed structural design allowables unless expressly confirmed in a project-specific specification, certified test report, or engineering submittal. Full-profile performance, local buckling, connection capacity, fastener behavior, creep, fatigue, deflection, and project-specific loading must be evaluated separately.
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