Two-Hole Blade End Fitting for Composite Insulator
The two-hole blade end fitting is a galvanized metal component designed for use at the end of a composite insulator. Its cylindrical sleeve is fitted over the fiberglass-reinforced polymer core rod and permanently secured using a controlled crimping process. The flat blade provides two connection holes for assembly with a crossarm, mounting bracket, conductor fitting or other approved line hardware.
This end fitting is suitable for customized composite suspension, tension or line-post insulator assemblies when its dimensions, material, crimping profile and mechanical rating match the complete insulator design. The component must not be selected independently from the fiberglass core rod and the finished insulator mechanical requirements.
Important: The product photograph shows an unassembled metal end fitting only. It does not represent a complete composite insulator. Voltage rating, specified mechanical load and application type cannot be determined from the metal fitting alone.
Key Features
- Two-hole flat blade connection structure
- Cylindrical sleeve designed for attachment to an FRP core rod
- Rounded blade end to reduce sharp edges around the connection area
- Hot-dip galvanized surface option for outdoor corrosion protection
- Hole diameter and center distance can be customized
- Sleeve bore and crimping dimensions can match the specified core rod
- Suitable for suspension, tension or line-post insulator designs when verified
- Custom material, dimensions, marking and packaging available
Typical Technical Specifications
| Product Type | Composite Insulator Metal End Fitting |
|---|---|
| Connection Type | Two-Hole Blade / Two-Hole Tongue |
| Insulator-Side Structure | Cylindrical Crimping Sleeve |
| Number of Connection Holes | Two |
| Material | Carbon steel, forged steel or cast steel according to the approved drawing |
| Surface Treatment | Hot-dip galvanized |
| Core-Rod Compatibility | Manufactured according to the specified FRP rod diameter |
| Assembly Method | Controlled radial or project-specified crimping |
| Application | Composite suspension, tension or line-post insulator assemblies |
| Dimensions | According to customer drawing or approved insulator design |
| Mechanical Rating | Subject to the complete insulator design and mechanical test report |
| Customization | Sleeve bore, blade width, blade thickness, hole diameter, hole spacing, material and coating |
Final dimensions and mechanical performance must be confirmed from the approved drawing and test data. The photograph cannot establish the applicable core-rod diameter, voltage class or specified mechanical load.
Structure and Function
Two-Hole Blade
The flat blade provides two connection positions for bolted assembly with compatible utility hardware. Hole diameter, center distance, blade thickness and edge distance must match the project drawing to prevent interference, excessive clearance or localized stress.
Crimping Sleeve
The cylindrical section receives the fiberglass-reinforced core rod of the composite insulator. Its internal diameter, wall thickness, effective crimping length and surface condition must be coordinated with the core-rod diameter and the validated crimping process.
Bottom Collar
The enlarged collar at the end of the sleeve forms part of the component geometry. Its dimensions and function must follow the approved insulator design and should not be altered without mechanical validation.
Material and Manufacturing
The end fitting may be manufactured from forged carbon steel, cast steel or another approved metallic material. The exact material grade and production method must be selected according to the required mechanical load, crimping behavior, dimensional tolerances and environmental conditions.
Critical areas should be checked for cracks, porosity, laps, sharp edges and other defects that could affect crimping or mechanical performance. The sleeve bore and connection holes should be dimensionally inspected before assembly.
Surface Protection
Hot-dip galvanizing may be applied to protect the steel component against atmospheric corrosion. Coating thickness, adhesion, appearance and test method should be specified in the purchase order or approved drawing.
ISO 1461 may be used as a reference for general hot-dip galvanized coating requirements. Where crimping affects the galvanized surface, the complete manufacturing and assembly process must be validated to ensure that coating damage does not compromise the finished insulator.
Typical Applications
- Composite suspension insulators
- Composite tension insulators
- Composite line-post insulators
- Substation composite insulator assemblies
- Railway electrification insulators when designed for the application
- Customized polymer-insulator connection systems
Assembly Considerations
- Confirm the FRP core-rod diameter and end-fitting sleeve bore.
- Inspect the sleeve bore for contamination, corrosion or dimensional defects.
- Insert the prepared core rod to the specified assembly depth.
- Use the approved crimping dies, crimping sequence and process parameters.
- Inspect the crimped profile and final dimensions.
- Perform the required mechanical verification on the completed insulator.
- Protect the core-to-fitting interface using the approved sealing design.
Crimping parameters must be established through process qualification. Excessive crimping can damage the fiberglass core, while insufficient crimping can reduce pull-out strength.
Quality Inspection
- Raw-material verification
- Overall dimensional inspection
- Blade thickness and width inspection
- Connection-hole diameter and spacing inspection
- Sleeve internal diameter and effective length inspection
- Surface-defect inspection
- Galvanized-coating inspection when specified
- Crimping-process verification
- Mechanical tensile or bending test on the completed insulator assembly
Reference Standards
- IEC 61109:2025 – Composite suspension and tension insulators
- IEC 61466-1:2016 – Standard strength classes and end fittings for composite string insulator units
- IEC 61952-1:2019 – Composite line-post insulator definitions, end fittings and designations
- IEC 62217:2025 – General requirements and tests for polymeric insulators
- ISO 1461:2022 – Hot-dip galvanized coatings on fabricated iron and steel articles
- Customer drawings and approved insulator technical specifications
Reference to these standards does not constitute product certification. Compliance must be demonstrated using the drawing, inspection records and test reports for the exact end fitting and complete insulator assembly.
Ordering Information
Please provide the following information when requesting a quotation:
- Complete end-fitting drawing
- FRP core-rod diameter
- Sleeve internal diameter and crimping length
- Blade width and thickness
- Connection-hole diameter and center distance
- Required material grade
- Required galvanized-coating specification
- Insulator type and application
- Specified mechanical load
- Required inspection and test documents
- Order quantity, marking and packaging
Frequently Asked Questions
Is this a complete composite insulator?
No. This product is a metal end fitting used as one component of a composite insulator assembly.
Can the voltage rating be selected from the end fitting alone?
No. The voltage rating depends mainly on the complete insulator design, including insulating length, creepage distance, housing profile and system requirements.
Can the sleeve fit different fiberglass core rods?
The sleeve dimensions must match the specified core-rod diameter and validated crimping process. One sleeve size should not be assumed to fit every core rod.
Can the mechanical load be guaranteed before crimping?
The final mechanical performance depends on the fitting material, core rod, sleeve dimensions, crimping parameters and complete insulator assembly. It must be verified by testing the finished assembly.
Can the hole size and spacing be customized?
Yes. Blade dimensions, hole diameter and center distance can be manufactured according to the approved customer drawing.
