Epoxy glass fiber 3240 threaded rod

Description

What is 3240 Threaded Rod?

3240 threaded rod is a high-performance electrical insulation fastener manufactured by precision machining threaded patterns onto rods cut from 3240 epoxy phenolic glass fiber laminate sheets. This material is produced by layering woven glass fiber cloth, impregnating it with epoxy-phenolic resin, and curing under high temperature and pressure to create a dense, durable composite.

Unlike standard threaded rods, 3240 rods provide dual functionality: secure mechanical fastening combined with superior electrical insulation, making them indispensable in high-voltage and high-temperature environments where metallic fasteners would cause short circuits or thermal issues.

Manufacturing Process

At SIDA, our production follows stringent quality protocols:

Material Selection: Premium 3240 sheets conforming to GB/T1303.1-1998 standard
Precision Cutting: Water-jet or diamond-saw cutting into rod blanks per customer specifications
CNC Threading: High-precision CNC machining creates standard (M4-M30) or custom threads
Quality Inspection: 100% dimensional check + sample electrical/mechanical testing
Surface Treatment: Deburring and cleaning to ensure smooth, defect-free surfaces

Key Performance Advantages

Economic Efficiency: 15-25% cost savings compared to FR4 threaded rods, ideal for large-scale projects
Balanced Performance: Excellent mechanical-electrical property ratio for B-class applications
Dimensional Stability: Low moisture absorption (21.5mg) ensures stable performance in humid conditions
Processability: Easy to machine, cut, and thread without delamination
Standard Compliance: Meets international IEC 60893 and Chinese GB/T1303.1 standards

3240 vs FR4: Making the Right Choice

Feature	3240 (Epoxy Phenolic)	FR4 (Epoxy)	Recommendation
Cost	★★★★★ (Lower)	★★★☆☆	Choose 3240 for budget-conscious projects
Mechanical Strength	Good (345 MPa)	Excellent (≥400 MPa)	FR4 for extreme load applications
Temperature Class	B (130°C)	F (155°C)	3240 for ≤130°C environments
Moisture Resistance	Very Good (21.5mg)	Excellent (≤20mg)	Both suitable for humid conditions
Dielectric Strength	10.4 kV/mm	16-20 kV/mm	FR4 for ultra-high voltage

Bottom Line: For applications within 130°C and moderate mechanical loads, 3240 provides optimal value without compromising safety or performance.

4. Technical Data Tables

3240 Threaded rods Technical Data Sheet

Properties	Unit	Index Value	Fact Value
Flexural Strength perpendicular to laminations A: under normal conditions E-1/150: 150±5 ℃	Mpa	≥340	345
Impact Strength parallel to laminations (Charpy)	KJ/m2	≥33	34.5
Tensile Strength	Mpa	≥300	300
Insulation Resistance after immersion in water (D-24/23)	W	≥5.0×10 8	5.1×108
Dielectric Strength perpendicular to laminations (in 90±2 ℃ transformer oil, 1 mm)	KV/mm	≥10.2	10.4
Breakdown Voltage parallel to laminations (in 90±2℃ transformer oil)	KV	≥35	36.1
Permittivity (50Hz)		≤5.5	5
Permittivity (1MHz)		≤5.5	5.1
Dissipation Factor (50Hz)		≤0.04	0.032
Dissipation Factor (1MHz)		≤0.04	0.032
Water Absorption (D-24/23, 1.6mm)	≤mg	34	21.5
Density	g/cm3	(1.70-2.0)	1.96
Reference Standard		GB/T1303.1-1998

Note:The product specifications provided are for reference purposes only. Please refer to the actual product for final specifications. We also offer various sizes and thicknesses to meet your specific needs. For further customization, please contact us.

5. Application Scenarios

Electrical Switchgear & Control Panels

Why it matters: 3240 rods provide secure mounting of live components while preventing phase-to-phase short circuits. Their 130°C rating handles heat from contactors and thermal relays.

Typical uses: Busbar supports,断路器 (circuit breaker) insulation, terminal block mounting, door hinge insulation.

Power Transformers (Oil & Dry Type)

Why it matters: With 10.4 kV/mm dielectric strength and oil compatibility, 3240 rods maintain structural integrity under transformer oil immersion.

Typical uses: Core clamping bolts, winding support rods, tap changer insulation, lead wire fastening.

Motors & Generators

Why it matters: B-class temperature rating matches standard motor insulation systems. Low dissipation factor (0.032) minimizes dielectric losses at 50/60Hz.

Typical uses: End winding bracing, rotor balance weight fastening, terminal box insulation.

High-Voltage Equipment (≤35kV)

Why it matters: 36.1 kV parallel breakdown voltage provides safety margin in medium-voltage applications like ring main units and switchyards.

Typical uses: Insulating spacers, surge arrester mounts, capacitor bank hardware.

Railway & Metro Systems

Why it matters: Excellent impact strength (34.5 kJ/m²) withstands vibration and mechanical shock in rolling stock applications.

Typical uses: Traction converter mounting, auxiliary power supply insulation, signaling equipment fastening.

New Energy (Solar/Wind Power)

Why it matters: Cost-effective for large inverter installations. Good UV resistance and moisture stability ensures 20+ year service life.

Typical uses: PV combiner box insulation, wind turbine control cabinet mounting, power converter fastening.

6. Frequently Asked Questions (FAQs)

Q1: What is the difference between 3240 and FR4 threaded rods?

A: Both are epoxy-glass composites, but 3240 uses epoxy-phenolic resin while FR4 uses pure epoxy. This makes 3240 more economical (15-25% cheaper) with slightly lower mechanical strength (345 vs 400+ MPa) and temperature rating (130°C B-class vs 155°C F-class). Choose 3240 for cost-sensitive applications under 130°C; FR4 for high-performance demands.

Q2: Can I use 3240 threaded rod in 155°C environments?

A: No. 3240 is rated for 130°C continuous operation (Class B). Exceeding this degrades mechanical and electrical properties. For 155°C applications, use FR4 (Class F) or G11 (Class H). Short-term peaks up to 150°C are acceptable for <2 hours.

Q3: Is customization available for non-standard sizes?

A: Absolutely. SIDA offers full CNC machining services for diameters Ø3-50mm, lengths up to 2000mm, and custom threads (UNC, UNF, BSW). Provide your drawings and we deliver precision-machined rods in 7-15 days.

Q4: How does 3240 compare to G10/G11?

A: G10/G11 are NEMA standards for epoxy-glass laminates. 3240 is the Chinese GB equivalent to G10 (general purpose) but with phenolic modification. G11 has higher temperature resistance (180°C) but costs 40% more. 3240 offers the best value for B-class applications.

Q5: Is your 3240 threaded rod RoHS compliant?

A: Yes. Our material is fully RoHS 3 (2015/863) compliant, containing no lead, mercury, cadmium, or other restricted substances. We provide certificates of compliance with each shipment.

Q6: What is the typical lead time and MOQ?

A: Standard sizes (M4-M12) ship from stock in 3-5 days. Custom sizes have a 7-15 day lead time. MOQ is 100 pieces for standard sizes, 500 pieces for custom orders. Sample orders (10 pcs) welcome for testing.

Q7: How should I store 3240 threaded rods?

A: Store in dry, ventilated areas away from direct sunlight and heat sources. Keep in original packaging until use. While water absorption is low (21.5mg), prolonged humidity can affect surface resistivity. Shelf life: 5 years under proper conditions.

7. Quality Assurance & Certifications

Standards Compliance: GB/T1303.1-1998, IEC 60893-3-2, NEMA LI-1
Test Reports: Available for dielectric strength, flammability (UL94 V-0), and RoHS
Quality System: ISO 9001:2015 certified manufacturing
Traceability: Lot numbers on each batch for material tracking
Inspection: 100% dimensional check + 5% sampling for electrical tests

8. Why Choose SIDA for 3240 Threaded Rods?

✓ Factory-Direct Pricing: 15% lower than trading companies, volume discounts available
✓ Precision Machining: ±0.1mm tolerance guarantee with CNC threading
✓ Fast Delivery: 3-5 days for stock items, 7-15 days for custom orders
✓ Technical Support: Free material selection consultation and design review
✓ Proven Track Record: 10+ years supplying State Grid, CRRC, and ABB partners

9. Related Products & Content

Internal Links:

FR4 Threaded Rod (for high-temp applications)
3240 Insulation Sheets (raw material)
Epoxy Glass Fiber Nuts & Washers
Technical Guide: “How to Select Insulation Fasteners”

External Citations:

GB/T1303.1-1998: Industrial Rigid Laminated Sheets
IEC 60893-3-2: Specifications for Epoxy Industrial Rigid Laminated Sheets
NEMA LI-1: Industrial Laminated Thermosetting Products