Product Overview
Heavy-duty pultruded GRP (Glass Reinforced Plastic) square tube engineered for structural applications requiring corrosion resistance, electrical insulation, and high strength-to-weight ratio. The 7mm wall thickness provides high load-bearing capacity for handrail systems, platforms, and structural frameworks in demanding industrial environments.
Manufacturing Process: Continuous pultrusion with longitudinally aligned continuous glass fiber rovings in thermosetting resin matrix, ensuring consistent mechanical properties throughout the profile length.
Technical Specifications
Dimensional Properties
| Parameter | Value |
|---|---|
| Profile Type | Square Hollow Tube |
| External Dimensions | 80mm × 80mm |
| Internal Dimensions | 66mm × 66mm |
| Wall Thickness | 7mm |
| Cross-Sectional Area | 21.0 cm² (approximate) |
| Weight per Meter | 4.2 kg/m (approximate) |
| Moment of Inertia (Ixx, Iyy) | ~52 cm⁴ |
| Section Modulus (Wxx, Wyy) | ~13 cm³ |
Material Composition
- Matrix Resin: Isophthalic Polyester or Vinyl Ester
- Reinforcement: Continuous E-Glass Fiber Rovings
- Fiber Content: 55-65% by weight
- Surface Protection: UV-Resistant Polyester Veil
- Density: 1.8-2.1 g/cm³
Mechanical Properties
Note: Properties are directional due to pultrusion process. Longitudinal = along fiber direction (length). Transverse = perpendicular to fibers.
| Property | Longitudinal | Transverse | Test Method |
|---|---|---|---|
| Tensile Strength | 240-280 MPa | 60-80 MPa | ASTM D638 |
| Tensile Modulus | 23-26 GPa | 8-10 GPa | ASTM D638 |
| Flexural Strength | 300-350 MPa | 100-140 MPa | ASTM D790 |
| Flexural Modulus | 20-23 GPa | 7-9 GPa | ASTM D790 |
| Compressive Strength | 220-260 MPa | 120-150 MPa | ASTM D695 |
| Interlaminar Shear Strength | 20-30 MPa | – | ASTM D2344 |
| Barcol Hardness | 40-50 | – | ASTM D2583 |
Physical & Thermal Properties
| Property | Value | Test Method |
|---|---|---|
| Water Absorption (24hr) | < 0.5% | ASTM D570 |
| Coefficient of Thermal Expansion (Long.) | 8-10 × 10⁻⁶/°C | ASTM D696 |
| Coefficient of Thermal Expansion (Trans.) | 21-26 × 10⁻⁶/°C | ASTM D696 |
| Thermal Conductivity | 0.3-0.5 W/m·K | – |
| Heat Deflection Temperature @ 1.82 MPa | 130-150°C | ASTM D648 |
| Continuous Service Temperature | -40°C to +80°C | – |
| Flame Spread Index | ≤25 (Class A with FR resin) | ASTM E84 |
| Smoke Developed Index | ≤450 | ASTM E84 |
Electrical Properties
| Property | Value | Test Method |
|---|---|---|
| Dielectric Strength | 15-20 kV/mm | ASTM D149 |
| Volume Resistivity | > 10¹² Ω·cm | ASTM D257 |
| Arc Resistance | 180+ seconds | ASTM D495 |
| Electrical Classification | Non-conductive | – |
Performance Characteristics
Corrosion Resistance
Excellent resistance to:
- Dilute acids (sulfuric, hydrochloric, phosphoric up to 30% concentration)
- Alkalis (sodium hydroxide, potassium hydroxide)
- Saltwater and chloride environments
- Wastewater and sewage
- Chlorine and hypochlorite solutions
- Most organic solvents (excluding concentrated aromatics)
Limited resistance to:
- Concentrated acids (>50%)
- Concentrated aromatic hydrocarbons (benzene, toluene)
- Strong oxidizers at elevated temperatures
Service life: depends on the specific environment and load conditions; GRP profiles can provide long service life in compatible corrosive environments without regular protective coatings.
Weight Comparison
| Material | Section Size | Weight (kg/m) | Weight vs Steel |
|---|---|---|---|
| GRP Pultruded | 80×80×7mm | 4.2 | Reference |
| Carbon Steel SHS | 80×80×6mm | 14.0 | +233% |
| Stainless Steel 316 SHS | 80×80×6mm | 13.8 | +229% |
| Aluminum 6061 SHS | 80×80×6mm | 4.9 | +17% |
Non-Conductive Properties
- Electrical insulation: Does not conduct electricity – eliminates shock hazards
- Thermal insulation: Thermal conductivity ~100× lower than steel
- No grounding required: Suitable for use near electrical equipment
- EMI transparent: Does not interfere with electromagnetic signals
Design Load Capacity Data
Beam Capacity (Simply Supported, Uniformly Distributed Load)
| Span Length | Safe Working Load (UDL) | Deflection at SWL |
|---|---|---|
| 1.5m | 5.0 kN/m | 4.2mm (L/357) |
| 2.0m | 3.8 kN/m | 7.4mm (L/270) |
| 2.5m | 2.5 kN/m | 11.5mm (L/217) |
| 3.0m | 1.8 kN/m | 16.7mm (L/180) |
Design basis: Fixed ends, safety factor 3.0, deflection limit L/240.
Column Capacity (Axial Compression)
| Effective Length | Buckling Load (Euler) | Safe Working Load | Slenderness Ratio |
|---|---|---|---|
| 1.0m | 85 kN | 28 kN | 31 |
| 1.5m | 38 kN | 13 kN | 47 |
| 2.0m | 21 kN | 7 kN | 62 |
| 2.5m | 14 kN | 5 kN | 78 |
Design basis: Pinned-pinned end conditions, safety factor 3.0.
Handrail Stanchion Performance
Configuration: 1100mm height, fixed base, lateral load at top
| Load Condition | Applied Load | Deflection | Status |
|---|---|---|---|
| OSHA 1910.23 requirement | 890 N (200 lbf) | 18mm | ✓ Pass |
| EN ISO 14122-3 requirement | 300 N | 6mm | ✓ Pass |
| Design load (typical) | 1000 N | 20mm | ✓ Pass |
Primary Applications
Structural Framework
- Platform beams and supports (2.0-3.5m spans)
- Access ladder stringers (vertical and inclined)
- Equipment mounting frames
- Walkway and grating support structures
Safety Barrier Systems
- Handrail vertical stanchions (post spacing: 1.0-1.5m)
- Top rail horizontal members
- Mid-rail supports
- Toe board brackets
Industrial Infrastructure
- Chemical processing plant structures
- Wastewater treatment platforms and walkways
- Offshore platform handrails and access systems
- Electrical substation barriers and platforms
- Food processing equipment supports
- Marine and coastal structures
Suitable Environments
✓ High humidity and wet conditions
✓ Chemical exposure (acids, alkalis, solvents)
✓ Saltwater and marine atmospheres
✓ Near electrical equipment (non-conductive requirement)
✓ Temperature range: -40°C to +80°C
✓ UV exposure (with surface veil)
Not Recommended For
✗ Continuous exposure above 80°C
✗ Direct flame contact (unless FR-rated resin specified)
✗ Concentrated aromatic hydrocarbon immersion
✗ Applications requiring welding or heat forming
✗ High-impact ballistic applications
Fabrication & Installation Guidelines
Cutting
Recommended Tools:
- Hand saw: Fine-tooth (10-12 TPI) for small quantities
- Circular saw: Carbide-tipped blade or abrasive cut-off wheel
- Band saw: Fine-tooth bi-metal blade (6-10 TPI)
Best Practices:
- Support both sides of cut to prevent vibration
- Use low feed rate to prevent delamination
- Wear dust mask and eye protection (glass fiber dust)
- Deburr edges with sandpaper (120 grit)
Drilling
Drill Specifications:
- Bit type: Sharp HSS or carbide-tipped
- Drill speed: 300-500 RPM for 8-12mm holes
- Pilot holes: Recommended for holes >12mm diameter
Technique:
- Back profile with wood block to prevent breakout
- Use steady, moderate pressure
- Clear chips frequently
- Deburr holes after drilling
Connection Methods
1. Mechanical Fastening
Bolt Specifications:
- Material: Stainless steel 316, or GRP bolts
- Size: M10 to M16 for structural connections
- Washers: Large-diameter washers both sides (minimum 3× bolt diameter)
- Edge distance: Minimum 2.5× bolt diameter from edge
- Spacing: Minimum 4× bolt diameter between fasteners
Torque Guidelines:
| Bolt Size | Recommended Torque | Maximum Torque |
|---|---|---|
| M10 | 15-20 Nm | 25 Nm |
| M12 | 20-25 Nm | 35 Nm |
| M16 | 30-40 Nm | 50 Nm |
Note: Over-tightening can crush the profile. Use torque wrench.
2. Adhesive Bonding
Adhesive Type: Two-part structural epoxy (e.g., Sikadur 330, Araldite 2015)
Surface Preparation:
- Abrade surfaces with 80-grit sandpaper
- Remove dust with compressed air
- Clean with acetone or MEK
- Allow to dry completely
Application:
- Bond area: Minimum 25 cm² for structural joints
- Clamping pressure: 0.2-0.5 MPa
- Cure time: 24-48 hours at 20°C before loading
3. Mechanical Clamps
Use specialized GRP profile clamps or fabricated brackets:
- Include neoprene or rubber gaskets to distribute load
- Avoid point loading on profile walls
Support Spacing Recommendations
For Horizontal Beam Applications:
| Application Type | Maximum Support Spacing | Deflection Limit |
|---|---|---|
| Handrail top rail | 1.5m | L/240 |
| Platform beam (light duty) | 2.5m | L/240 |
| Platform beam (heavy duty) | 2.0m | L/360 |
| Equipment support | 2.0m | L/480 |
Quality Standards & Compliance
Manufacturing Standards
- ISO 9001:2015 – Quality Management System
- ASTM D3917 – Dimensional Tolerance of Thermosetting Glass-Reinforced Plastic Pultruded Shapes
- EN 13706 – Reinforced Plastics Composites – Specifications for Pultruded Profiles
Dimensional Tolerances
- External dimensions: ±1.5mm (per ASTM D3917)
- Wall thickness: ±0.5mm (±7% whichever is greater)
- Straightness: 5mm per 3m length maximum
- Squareness: 2° maximum deviation
Material Testing Standards
- ASTM D638 – Tensile Properties
- ASTM D790 – Flexural Properties
- ASTM D695 – Compressive Properties
- ASTM D2344 – Apparent Interlaminar Shear Strength
- ASTM D570 – Water Absorption
- ASTM D696 – Coefficient of Linear Thermal Expansion
- ASTM E84 – Surface Burning Characteristics
Relevant Design Codes
- OSHA 1910.23 – Walking-Working Surfaces (Guardrail Systems)
- EN ISO 14122-3 – Safety of Machinery – Permanent Means of Access
- ASCE Manual 104 – Structural Plastics Design Manual
- EUROCOMP Design Code – Structural Design of Polymer Composites
FAQ
What are the dimensions of 80x80x7mm fiberglass handrail profile?
80mm x 80mm square tube with 7mm wall thickness. Cross-sectional area 1490 mm², moment of inertia 0.87×10⁶ mm⁴, CE certified per EN13706 L3 standard for structural handrails.
This GRP square tube is manufactured as a pultruded FRP profile. We also supply related industrial FRP products such as pultruded FRP profiles, FRP rebar, pultrusion machines, and pultrusion dies.
What is the weight per meter?
2.68 kg/m (approximately 75% lighter than equivalent steel handrail tube). The lightweight profile can reduce structural support requirements and installation labor compared with galvanized or stainless steel profiles.
What is the modulus of elasticity?
25,000 MPa along fiber direction. Provides excellent stiffness for handrails, guardrails, and structural supports while meeting OSHA 1910.29 deflection limits (1/60 span maximum).
Does this profile meet OSHA handrail standards?
Yes. Complies with OSHA 1910.29(b) guardrails: 200 lbs concentrated load, 50 lbs/ft uniform load, top rail 42″ height ±3″. Safety factor 2.0 minimum per industry standards.
Is 80x80x7mm profile corrosion resistant?
Yes. Corrosion resistant in many industrial environments including moisture, saltwater, and industrial atmospheres. RAL 7035 light grey color standard. Long service life in compatible environments.
What applications use 80x80x7mm handrail profile?
Industrial platforms, process plant walkways, offshore platforms, chemical facilities, wastewater treatment, marine structures, and permanent guardrail systems requiring low-maintenance safety.
Is the profile electrically non-conductive?
Yes. Dielectric strength >100 kV/inch. Safe for electrical substations, live rail work, power plants, and hazardous locations where metal handrails pose electrical shock hazards.
Can 80x80x7mm profile be customized?
Yes. Custom lengths up to 6m, fire-retardant UL94 V0 resin, UV stabilized, special colors, and CNC fabrication for brackets/fittings. All-metal-free connections available.
Product Specifications
Available Configurations
Standard Lengths:
- 3.0 meters
- 4.0 meters
- 6.0 meters
Surface Finish:
- Smooth surface with UV-resistant veil (standard)
- Textured grip surface (handrail applications)
Color Options:
- Gray (RAL 7035 equivalent) – Standard
- Custom colors (other RAL colors)
Resin Systems:
- Isophthalic polyester (standard – general industrial use)
- Vinyl ester (enhanced chemical resistance)
- Fire-retardant polyester (Class A flame spread rating)
- Food-grade resin (FDA compliant – NSF 61 certified)
Documentation Available
- Material Test Certificates (MTC)
- Chemical resistance charts
- Fire rating certificates (ASTM E84, BS 476)
- CAD files (DWG, STEP, IGES formats)
- Structural calculation spreadsheets
- Material Safety Data Sheets (SDS)
Request a Quote for GRP Pultruded Square Tube 80x80x7mm
Need GRP pultruded square tube 80x80x7mm for handrails or structural frames? Contact us for a quote and we will confirm specifications, lengths, and lead time.
