technical of 3‑bolted type single tension guy‑wire clamps
1. Ultimate Tensile Strength (UTS)
1. This refers to the maximum tensile load the clamp can withstand before mechanical failure.
2. UTS of the clamp should match or exceed the Rated Tensile Strength (RTS) of the guy wire it anchors.
3. The clamp is tested as per IS 2486, ASTM A931, and IEC 61284.
2. Working Load / Safe Working Load (SWL)
1. SWL is typically 1/2.5 to 1/3 of UTS to ensure safe long-term operation.
2. Typical SWL Range:
I. 15 – 40 kN, depending on wire size and installation.
3. Designed to handle:
I. Dead-end tension
II. Wind, ice, and seismic loads
3. Conductor Diameter Compatibility
1. Specifically made to fit standard guy wire diameters.
2. Compatibility Range:
6 mm to 12 mm (approx. 1/4" to 1/2")
3. Must ensure tight seating of all seven strands without strand deformation.
4. Slip Strength:
1. Must resist slippage of the guy wire under high axial load.
2. Slip Resistance:
≥ 95% of the wire's RTS
3. Achieved by:
I. Proper torque of the 3 bolts (usually 30–50 Nm per bolt)
II. Serrated grooves and full contact grip area
5. Temperature Withstanding Capacity:
1. Designed for outdoor service life, including:
Cold winters, hot summers, and fault conditions
2. Operating Range:
I. -40°C to +120°C (standard)
II. Short-term up to 250°C under abnormal fault events
6. Corrosion Resistance:
1. Since guy wire clamps are used outdoors, they must resist:
I. Humidity
II. Acid rain
III. Salt spray (coastal areas)
2.Materials and Coating:
I. High-strength ductile iron or malleable iron
II. Hot-Dip Galvanized as per IS 2629 / ASTM A153
III. Minimum coating: 80–100 µm (610 g/m²)
7. Impact & Fatigue Strength:
1. Clamps must withstand:
I. Wind vibration (guy sway)
II. Pole flexing or movement
III. Installation impact
2. >10⁷ fatigue cycles
3. No loosening, cracking, or slipping under repeated dynamic loads
8. Mechanical Endurance:
1. Designed for 25–40 years of field life.
2. Withstands:
I. Daily load cycling
II. UV radiation
III. Seasonal temperature changes
Iv. Long-term axial tension
9. Design Safety Factors:
1. UTS vs SWL
≥ 2.5 – 3.0×
2. Slip Resistance
≥ 95% of wire RTS
3. Temperature Overload Margin
~2× normal temperature
4. Fatigue Cycle Resistance
≥ 10⁷ cycles
5. Zinc Coating Thickness
80–100 µm (ASTM A153 / IS 2629)
Top 5 Quality Assurance
1. Compliance with Relevant Standards
a. Designed and manufactured as per utility and industry standards such as:
I. IS 2486, IS 4091, or equivalent.
II. ASTM A153 (for galvanizing)
b. Ensures the clamp is suitable for use in high-load guying applications and meets mechanical safety standards.
2.Raw Material Quality Inspection
a.
Made from forged or cast malleable/ductile iron, galvanized steel bolts and nuts.
b. All raw materials are tested for:
I. Chemical composition (via spectrometer)
II. Mechanical strength (tensile and yield strength)
c. Supplied with Material Test Certificates (MT
3. Mechanical Load Testing
a. Each clamp is tested for:
I. Ultimate Tensile Strength (UTS) — Should withstand at least 90-95% of the guy wire strength.
II. Slip Strength — Should prevent wire slippage under rated tension.
III. Safe Working Load (SWL) is confirmed through sample destructive tests.
b. Verifies that the clamp will securely grip guy wires without deformation or failure.
4. Surface Protection and Galvanizing Quality
a. All iron/steel parts are hot-dip galvanized per IS 2629 / ISO 1461.
b. Galvanizing is tested for:
I. Zinc coating thickness (typically ≥ 85 microns)
II. Adhesion
III. Corrosion resistance (salt spray test)
c. Ensures long-term durability in outdoor environments.
5. Final Inspection, Marking & Documentation
a. 100% visual and dimensional inspection for:
I. Burrs, cracks, threading accuracy, and bolt fitment
b. Each clamp is clearly marked with:
I. Batch number, manufacturer’s logo, size/type
c. Delivered with:
I. Inspection report
II. Certificate of Conformance (CoC)
III.Mechanical & galvanizing test certificates