China · structural profiles
GB/T 31539-2015 provides the structural pultruded-profile specification route. Use the specified test methods, grade and acceptance criteria for the project.
References: SAMR · GB/T 31539-2015
Engineering / Material performance
Pultruded profile performance
From dimensional fit to chemical exposure: define the properties, test methods and conditions that matter for your FRP profile.
Review My SpecificationView Material Data
For glass-fiber thermoset profiles. Carbon, hybrid and special formulations require their own data.
01 / Define
Geometry + material
Start with the drawing, resin, reinforcement and surface finish. These establish what the test data applies to.
02 / Specify
Method + conditions
Name the standard and edition, direction, conditioning, temperature and acceptance value for each property.
03 / Verify
Report + supplied product
Match the tested specimen and report scope to the profile being offered. Agree any additional tests before production.
How to read these tables
Published references illustrate the property and its units. Product-specific values and drawing tolerances must be confirmed for the offered configuration. References to a standard do not assert certification or compliance.
A standard minimum, a typical published value, a measured batch result and a design allowable have different meanings. Use the material data page for the existing E23 table, and the evidence library for available documents.
01 / Performance
Dimensions & tolerances
Specify the finished profile against a controlled drawing. Cross-section size, wall thickness and delivered length each need their own acceptance limits.
Scroll the table horizontally to view methods and conditions.
| Property / unit | Value or specification | Test / specification route | Conditions to confirm |
|---|---|---|---|
| Width, depth & outside diametermm | Drawing-specificNominal size ± agreed deviation | GB/T 31539; EN 13706-2; ASTM D3917 | Identify open or closed section, size band and measurement points. State whether an internal or external dimension controls the fit. |
| Wall thickness & corner geometrymm | Drawing-specificMinimum / maximum thickness; agreed radii | Selected profile standard + approved drawing | Measure walls, webs and flanges separately. Specify radii and local transitions, especially near screw channels or mating features. |
| Cut length & end squarenessmm; ° | Drawing-specificLength allowance and end-cut deviation | Selected profile standard + cutting specification | Separate as-pultruded supply from precision-cut parts. Define cut-face sealing and machining allowances. |
| Straightness, bow & cambermm over stated length | Drawing-specificMaximum deviation over a defined gauge length | EN 13706-2; ASTM D3917 | Record support condition, measurement plane and gauge length. A per-metre value does not automatically define the full-length limit. |
| Twist, angularity & flatness° over length; mm | Drawing-specificSeparate limit for each geometric feature | EN 13706-2; ASTM D3917 | Name the reference face and measurement span. Check engagement and assembly clearance on the mating parts. |
| Surface quality & fabricated holesAgreed acceptance criteria | Drawing-specificVisual quality level and machining drawing | ASTM D4385; EN 13706-2; approved drawing | Define acceptable cracks, exposed fibers, chips and surface defects. Hole position and diameter need separate fabrication tolerances. |
There is no single ± tolerance for every pultruded shape. Confirm the standard, edition, size band, datum and measurement length before approving the drawing. ASTM D3917 uses inch-pound values as the normative units.
References: SAMR · GB/T 31539-2015 · BSI · EN 13706-2:2002 · ASTM · D3917-23 · ASTM · D4385-19 · NHC · Profile dimension tolerances
02 / Performance
Physical & mechanical properties
Pultruded FRP is directional. Report longitudinal (L / LW), transverse (T / CW), and through-thickness (Z) results separately, with the reinforcement and resin identified.
Scroll the table horizontally to view methods and conditions.
| Property / unit | Value or specification | Test / specification route | Conditions to confirm |
|---|---|---|---|
| Densityg/cm³ | Published reference1.72–1.94 · NHC published range | ASTM D792; ISO 1183-1; GB/T 1463 | Supplier benchmark only. Confirm density for the actual fiber fraction, fillers and resin before estimating weight. |
| Fiber / resin content% by mass or volume | Product-specificSpecify fraction and basis | ISO 1172 (glass / filler content); GB/T 2577 (resin content) | Mass fraction and volume fraction are different. Account for mineral fillers and identify the reinforcement system. |
| Tensile strength & modulus, L / TMPa; GPa | Product-specificDeclare grade and measured directional values | ISO 527-4/-5; ASTM D3039; GB/T 1447 | Select the method for the laminate and specimen. Include conditioning, coupon location, sample count and statistical basis. |
| Compression & flexure, L / TMPa; GPa | Product-specificSeparate strength from stiffness | ASTM D6641 (compression); ISO 14125 (flexure); GB/T 1448 / 1449 | Record the fixture and failure mode. Coupon flexural modulus and full-section effective modulus are separate results. |
| Full-section flexural stiffnessGPa; N·mm² | Product-specificReport effective modulus and section stiffness | EN 13706-2 | Identify section geometry, span, loading and test configuration; do not substitute a longitudinal tensile modulus. |
| Interlaminar shear & pin bearingMPa | Product-specificSeparate shear and bearing results | ISO 14130 (short-beam); EN 13706-2 (pin bearing) | Short-beam results are method-dependent and are not in-plane shear values. Connections also require hole, edge-distance and fastener checks. |
| Water absorption & Barcol hardness%; Barcol scale | Product-specificAgree conditioning and acceptance limits | ISO 62 / ASTM D570; ASTM D2583 / GB/T 3854 | State immersion time and temperature for absorption. Hardness indicates local surface condition and cannot replace mechanical testing. |
A coupon strength is not a beam load rating. Use verified material properties with section geometry, connections, creep, environmental reductions and the project design rules. E17 / E23 grade evidence must cover all required properties.
References: BSI · EN 13706-3:2002 · BSI · EN 13706-2:2002 · SAMR · GB/T 1447-2005 · ASTM · Composite test methods · ISO · Reinforced plastics standards · ASTM · D2583-25 · NHC · Physical properties
E17 / E23: selected reference minimums
Selected EN 13706-3 grade requirements, cross-checked against Fiberline’s published comparison. These are standard reference minimums, not F1 measured results or design allowables. L = longitudinal; T = transverse.
| Property | Unit | E17 minimum | E23 minimum |
|---|---|---|---|
| Tensile modulus · L | GPa | 17 | 23 |
| Tensile modulus · T | GPa | 5 | 7 |
| Tensile strength · L | MPa | 170 | 240 |
| Tensile strength · T | MPa | 30 | 50 |
| Flexural strength · L | MPa | 170 | 240 |
| Flexural strength · T | MPa | 70 | 100 |
| Apparent interlaminar shear strength | MPa | 15 | 25 |
This is a selected-property summary, not a complete grade acceptance checklist. Full-section stiffness, pin bearing and the other applicable requirements must also be verified. Compare with F1’s published material reference before requesting product-specific evidence.
References: BSI · EN 13706-3:2002 · Fiberline · EN 13706 grade comparison
03 / Performance
Thermal performance
Thermal insulation, dimensional movement and temperature capability answer different design questions. The resin, cure and fiber direction influence each result.
Scroll the table horizontally to view methods and conditions.
| Property / unit | Value or specification | Test / specification route | Conditions to confirm |
|---|---|---|---|
| Thermal conductivity, λW/(m·K) | Published reference0.3 · EPTA comparison value | GB/T 3399; ASTM C177, where specimen and apparatus are suitable | Industry illustration only. Request direction, mean test temperature, moisture condition and specimen thickness for the offered profile. |
| Coefficient of thermal expansion, α10⁻⁶/K | Published reference11 · EPTA comparison value | ASTM E831; GB/T 2572 | Confirm direction and temperature interval. Use ΔL = α × L × ΔT with consistent units; do not copy an ambiguous supplier unit. |
| Glass transition temperature, Tg°C | Product-specificMeasured for the selected formulation and cure | ISO 11357-2 (DSC); ASTM E1640 (DMA) | Name the method and transition criterion. DSC and DMA values need not coincide; wet conditioning may change performance. |
| Heat-deflection temperature, HDT°C at stated stress | Product-specificTest temperature under specified bending stress | ISO 75; ASTM D648 | Include applied stress and specimen orientation. HDT is not a continuous service-temperature rating. |
| Service temperature & thermal cycling°C; cycles; retained % | Product-specificProject-specific temperature envelope | Agreed aging / cycling and residual-property test plan | State continuous and peak temperatures, duration, moisture, sustained load, acceptable deflection and strength retention. |
Tg, heat-deflection temperature and continuous service temperature are different quantities. Define a service envelope using load, exposure time, moisture and property retention; a material conductivity alone does not establish a window U-value.
References: EPTA · Pultruded composites in rail · SAMR · GB/T 3399-1982 · ISO · 11357-2:2020 · NHC · Thermal properties
04 / Performance
Electrical insulation & conductivity
Glass-fiber profiles are commonly selected for electrical insulation, while carbon reinforcement or conductive additives can change conductivity. Specify the complete material and exposure conditions.
Scroll the table horizontally to view methods and conditions.
| Property / unit | Value or specification | Test / specification route | Conditions to confirm |
|---|---|---|---|
| Dielectric strengthkV/mm | Published reference200 V/mil ≈ 7.87 kV/mm · NHC PF example | ASTM D149; IEC 60243-1; GB/T 1408.1 | NHC labels this direction PF. Verify its orientation definition, specimen thickness, electrodes and dry / wet conditioning before comparison. |
| Volume resistivity / conductivityΩ·m / S/m | Product-specificSpecify insulation or conductive target | IEC 62631-3-1; ASTM D257 for insulating materials | Report direction, humidity, temperature and test voltage. Conductivity σ = 1/ρ for the corresponding direction and conditions; conductive composites need a suitable method. |
| Surface resistivityΩ | Product-specificDry and conditioned results | IEC 62631-3-2; ASTM D257 | Surface contamination, coatings and moisture matter. Do not confuse surface resistivity with volume resistivity. |
| Permittivity & dissipation factorRelative εr; tan δ | Product-specificValues at a specified frequency | ASTM D150 | Include frequency, temperature and conditioning; a 60 Hz result does not establish RF performance. |
| Dry arc resistance & trackings; method-specific index | Product-specificSeparate arc and tracking evaluations | ASTM D495 (dry arc); IEC 60112 (CTI / PTI) | Dry arc resistance and wet tracking are different phenomena. State the equipment environment and selected acceptance test. |
Dielectric breakdown strength is a laboratory result, not an operating-voltage rating. Equipment design must account for creepage, clearance, moisture, contamination, joints and the applicable equipment standard.
References: ASTM · D149-25 · ASTM · Electrical insulation methods · IEC · 62631-3-1:2023 · IEC · 62631-3-2:2023 · ASTM · D495-22 · SAMR · GB/T 1408.1-2016 · NHC · Electrical properties
05 / Performance
Fire, smoke & reaction to fire
Specify a fire requirement for the actual end use, resin formulation, thickness, finish and installation. A fire-retardant additive does not establish a classification on its own.
Scroll the table horizontally to view methods and conditions.
| Property / unit | Value or specification | Test / specification route | Conditions to confirm |
|---|---|---|---|
| Small-flame behavior of plastic partsClassification + thickness | Product-specificRequest the formulation-specific classification | UL 94 | Record tested thickness, color and material identification. This classification does not establish building-material fire compliance. |
| Surface burningFlame-spread / smoke-developed indices | Product-specificRequest both indices and mounting details | ASTM E84 | A flame-spread index alone is incomplete. Review the specimen, supporting substrate and intended installation. |
| Construction-product reaction to fireClassification and applicable suffixes | Product-specificDeclare the required market and end-use class | EN 13501-1; GB 8624 | Use the relevant classification report and its field of application. European and Chinese classes require their own evaluation. |
| Oxygen index% oxygen by volume | Product-specificMeasured LOI for the selected laminate | ISO 4589-2; ASTM D2863; GB/T 2406.2 | LOI is a test result under defined conditions, not a substitute for an end-use fire classification. |
| Smoke density & toxicityMethod-specific results | Product-specificAgree smoke and gas requirements separately | ASTM E662 (smoke density); application-specific gas testing | Optical smoke density does not quantify toxicity. Rail and marine projects need the tests and criteria for their particular application. |
UL 94 V-0, an E84 flame-spread result and an EN 13501-1 class are not interchangeable. Reaction-to-fire data also does not establish a load-bearing fire-resistance period.
China edition check · 21 September 2026: GB 8624-2012 remains current. GB 8624-2025 is published and takes effect on 1 January 2027. Confirm the edition required for the project approval date. SAMR implementation record.
References: UL · UL 94 scope and limitations · ASTM · Fire test methods · BSI · EN 13501-1:2018 · SAMR · GB 8624 editions · SAMR · GB 8624-2025 implementation
06 / Performance
Chemical resistance & durability
Build a compatibility decision around the chemical, concentration, temperature and contact mode. Resin-family charts are useful for screening; the exact cured laminate determines the offered performance.
Scroll the table horizontally to view methods and conditions.
| Property / unit | Value or specification | Test / specification route | Conditions to confirm |
|---|---|---|---|
| Chemical compatibilityChemical; concentration %; °C | Product-specificReview exact resin grade against exposure | GB/T 3857; ASTM D543; ISO 175 as applicable | Provide chemical names or composition, concentration basis, normal / maximum temperature and impurities. Methods cover related subjects but are not automatically equivalent. |
| Immersion, splash & vapor exposureh; exposure mode | Product-specificExposure cycle matched to service | Agreed chemical-resistance test programme | Continuous immersion differs from occasional splash. Define dwell time, drying, cleaning, stress and sample edge sealing. |
| Mass, dimensions & appearance% change; visual record | Product-specificBefore / after exposure comparison | ASTM D543; GB/T 3857 | Record swelling, cracking, blistering or exposed fibers together with the measurement and conditioning procedure. |
| Retained mechanical properties% of unexposed control | Product-specificAgree retained strength and stiffness limits | Exposure protocol + relevant mechanical method | Compare matched exposed and control specimens. A short immersion test does not establish a service life in years. |
| UV, moisture & outdoor agingExposure hours; retained % | Product-specificSeparate durability assessment | ISO 4892-3; ASTM G154; GB/T 2573, as applicable | Specify coating / veil, exposure cycle and residual properties. Appearance retention and structural retention are separate criteria. |
A chemical name or pH alone is insufficient. Include mixtures, cleaning chemicals, temperature excursions and sustained stress, then agree the acceptable change in mass, appearance and mechanical properties.
References: ASTM · D543-21 · SAMR · GB/T 3857-2017 · NHC · Chemical resistance
How resin and temperature change a screening result
Selected NHC supplier-chart examples, reproduced as a comparison reference. ISO here means isophthalic polyester; VE means vinyl ester. These are not F1 test results or approved service limits.
| Chemical / concentration | ISO · 20°C | ISO · 50°C | VE · 20°C | VE · 50°C |
|---|---|---|---|---|
| Hydrochloric acid · 20% | + | + | + | + |
| Potassium hydroxide · 10% | 0 | − | + | + |
| Acetic acid · 75% | 0 | − | + | + |
| Methyl ethyl ketone · 100% | − | − | − | − |
+ Good resistance in the source chart · 0 Possible attack; consider another resin · − Unsuitable in the source chart. The chart does not provide a complete exposure duration, stress or laminate specification; confirm compatibility for the actual supply.
References: NHC · Chemical resistance
Standards & scope
Choose a specification route
These documents have different jobs. Select the governing product specification, then the relevant property tests and end-use requirements. Listing several methods does not make their results interchangeable.
Europe · EN 13706 series
Part 1 covers designation; Part 2 covers test methods and general requirements; Part 3 covers grade requirements. E17 and E23 are profile grades, not fire or insulation classes.
References: BSI · EN 13706-2:2002 · BSI · EN 13706-3:2002
United States · ASTM methods
D3917 addresses dimensions; D4385 addresses visual defects. Mechanical, thermal, electrical and fire properties require their relevant tests and agreed acceptance values.
References: ASTM · D3917-23 · ASTM · D4385-19 · ASTM · Composite test methods
Test result → engineering design
Define whether a value is a mean, minimum or characteristic result. Establish member and connection capacity with the governing design rules, load duration and environmental factors.
References: ASTM · Composite test methods
FROM REFERENCE TO RFQ
Build a testable specification
- 1. Product: profile drawing and revision, cut length, tolerances, resin, reinforcement, finish and quantity.
- 2. Service: load direction and duration, temperature range, UV / moisture, chemicals and contact mode.
- 3. Acceptance: each target or minimum, standard and edition, specimen direction, conditioning and sampling frequency.
- 4. Evidence: report identification, specimen match, batch traceability and any independent or witnessed testing required.
Source library
Standards and published references
Reviewed 21 September 2026. Public catalogue records establish document identity and scope; use the licensed standard and the agreed edition for contractual limits and complete procedures. Supplier and industry examples remain separately attributed.
Browse all 31 references
- SAMR · GB/T 31539-2015
Chinese specification for structural pultruded FRP profiles.
- BSI · EN 13706-2:2002
Pultruded-profile test methods and general requirements.
- BSI · EN 13706-3:2002
Properties and requirements for profile grades.
- Fiberline · EN 13706 grade comparison
Manufacturer-published summary used to cross-check selected E17 / E23 reference minimums; not an F1 test report.
- ASTM · D3917-23
Production tolerances for thermoset glass-reinforced pultruded shapes; custom tolerances can differ.
- ASTM · D4385-19
Visual defect classification and acceptance criteria.
- ASTM · D2583-25
Barcol indentation hardness of rigid plastics.
- ASTM · Composite test methods
Mechanical test methods and D7290 characteristic-value evaluation.
- SAMR · GB/T 1447-2005
Tensile testing of fiber-reinforced plastic composites.
- SAMR · GB/T 3399-1982
Thermal conductivity by guarded hot plate; catalogue lists it as current.
- ISO · 11357-2:2020
Glass transition temperature by differential scanning calorimetry.
- ISO · Reinforced plastics standards
Catalogue includes ISO 14125 flexure and ISO 14130 apparent interlaminar shear testing.
- EPTA · Pultruded composites in rail
Industry comparison values, including thermal conductivity and thermal expansion; not product certification.
- ASTM · D149-25
Breakdown voltage and dielectric strength at commercial power frequencies.
- ASTM · Electrical insulation methods
Methods for electrical properties, resistivity and insulation evaluation.
- IEC · 62631-3-1:2023
DC measurement of volume resistance and resistivity of insulating materials.
- IEC · 62631-3-2:2023
DC measurement of surface resistance and resistivity of insulating materials.
- ASTM · D495-22
High-voltage, low-current dry arc resistance; distinct from Barcol hardness.
- SAMR · GB/T 1408.1-2016
Electric strength of insulating materials at power frequencies.
- UL · UL 94 scope and limitations
Small-scale plastic flammability classifications do not establish building-product fire performance.
- ASTM · Fire test methods
E84 surface burning, E662 smoke density and other fire response tests.
- BSI · EN 13501-1:2018
Reaction-to-fire classification of construction products.
- SAMR · GB 8624 editions
GB 8624-2012 is current at review; GB 8624-2025 takes effect on 1 January 2027.
- SAMR · GB 8624-2025 implementation
Published 31 December 2025; replaces the 2012 edition from 1 January 2027.
- ASTM · D543-21
Chemical exposure evaluation; specify reagent, concentration, temperature, time and stress.
- SAMR · GB/T 3857-2017
Chemical resistance testing of glass-reinforced thermosetting plastics.
- NHC · Profile dimension tolerances
Supplier reference for the dimensional specification structure; its tolerance classes are not F1 acceptance limits.
- NHC · Physical properties
Supplier-published density benchmark. Other entries need method and specimen verification.
- NHC · Thermal properties
Background reference; thermal expansion units and formulation-specific fire claims were not adopted as F1 data.
- NHC · Electrical properties
Supplier-published electrical examples; confirm specimen direction, thickness and conditions.
- NHC · Chemical resistance
Supplier comparison of isophthalic polyester and vinyl ester at 20 °C and 50 °C; not a project approval.
Quick Answers
Profile performance questions
Does E23 establish fire, electrical or chemical performance?
No. EN 13706 grade requirements concern specified profile properties. Fire behavior, electrical insulation and resistance to a particular chemical exposure need their own evidence for the supplied formulation and configuration.
Can I specify one tolerance for every profile dimension?
Specify dimensions individually against the applicable size bands, features and agreed standard. Cross-section dimensions, thickness, straightness, twist and cut length need distinct limits and measurement conditions.
Can glass-fiber insulation data be used for carbon-fiber profiles?
No. Carbon reinforcement and conductive additives can change electrical behavior. Use electrical test data for the actual resin, reinforcement, coating and conditioning, with the test direction stated.
What should accompany a performance requirement?
Send the section drawing, resin and reinforcement preference, service conditions, test standard and edition, target or minimum value, sampling plan and required report. F1 can then review the offered configuration and identify any additional testing needed.
Specify the performance your application needs
Send the dimensions, quantity, service environment, and destination. We acknowledge requirements within one business day.