UL-7 Extended U-Type Shackle Link Fitting – 70kN
The UL-7 extended U-type shackle is a load-bearing link fitting for overhead transmission lines, distribution lines and substation connection assemblies. It is used to connect insulator strings, line fittings, pole or tower attachment points and other hardware where additional connection length is required.
Compared with a standard U-type shackle, the UL-type shackle has an elongated forged body that provides increased clearance and assembly length. The bolt-type pin, nut and retaining cotter pin allow the fitting to be installed and inspected as part of a mechanical line-hardware assembly.
Reference Technical Data
| Product Type | Extended U-Type Shackle Link Fitting |
|---|---|
| Reference Model | UL-7 |
| Nominal Failure Load | 70kN |
| Dimension C | 20 mm |
| Pin Diameter d | 16 mm |
| Connection Width B | 16 mm |
| Overall Length L | 120 mm |
| Inside Radius R | 15 mm |
| Reference Weight | Approximately 0.65 kg |
| Body Material | Forged carbon steel |
| Surface Treatment | Hot-dip galvanized |
| Fastening Method | Bolt, nut and retaining cotter pin |
| Application | Overhead-line and substation link assemblies |
Important: The technical data above describes a representative UL-7 configuration. Dimensions and weight may vary between approved drawings. The purchaser must confirm the required load class, connection dimensions, galvanizing specification and mating hardware before ordering.
Key Features
- Extended U-shaped body provides additional assembly length and clearance
- Designed for mechanical connection of overhead-line fittings
- Forged-steel construction for load-bearing line-hardware assemblies
- Hot-dip galvanized surface provides corrosion protection for outdoor service
- Bolt, nut and retaining cotter pin help prevent unintended pin withdrawal
- Compatible with matching insulator-string and pole-line connection fittings
- Available in multiple mechanical load classes from 70kN to 210kN and above
- Dimensions and galvanizing requirements can be produced according to approved drawings
Materials and Surface Treatment
| Shackle Body | Forged carbon steel |
|---|---|
| Load Pin / Bolt | Steel, according to the approved drawing |
| Nut | Steel hexagonal nut |
| Retaining Pin | Stainless-steel cotter pin or approved equivalent |
| Coating | Hot-dip galvanized |
| Coating Requirement | According to DL/T, ISO 1461 or purchaser-approved specification |
Applications
- Overhead transmission-line connection assemblies
- Overhead distribution-line hardware
- Insulator-string connections
- Suspension-clamp assemblies
- Tension and dead-end assemblies
- Crossarm, pole and tower attachment points
- Substation outdoor connection fittings
- Guy-wire and stranded-wire attachment assemblies when specified by the drawing
Available Reference Models
| Model | C (mm) | d (mm) | B (mm) | L (mm) | R (mm) | Nominal Failure Load | Reference Weight |
|---|---|---|---|---|---|---|---|
| UL-7 | 20 | 16 | 16 | 120 | 15 | 70kN | 0.65 kg |
| UL-10 | 22 | 18 | 18 | 140 | 17 | 100kN | 0.92 kg |
| UL-12 | 24 | 22 | 20 | 140 | 18 | 120kN | 1.40 kg |
| UL-16 | 26 | 24 | 22 | 140 | 19 | 160kN | 1.64 kg |
| UL-21 | 30 | 27 | 24 | 160 | 22 | 210kN | 2.90 kg |
Reference dimensions are used for preliminary selection only. The approved manufacturing drawing controls the final product.
Selection Information Required
- Required model or nominal failure load
- Assembly drawing and connection orientation
- Required pin diameter
- Required internal width and overall length
- Mating fitting dimensions
- Steel grade or mechanical-property requirement
- Hot-dip galvanizing standard and coating thickness
- Marking, inspection and test-document requirements
- Packaging and project identification requirements
Standards and Quality Control
UL-type shackles may be manufactured and inspected with reference to DL/T 759-2023 for link fittings. IEC 61284 may be specified for overhead-line fittings when applicable to the project. Hot-dip galvanized coating can be supplied according to ISO 1461 or the purchaser’s approved coating specification.
Compliance with any standard must only be stated when the supplied model is supported by the corresponding drawing, inspection records and test documentation. Typical inspections may include dimensional verification, visual inspection, galvanizing inspection and mechanical load testing.
Installation Notes
- Verify the model, load class and mating dimensions before installation
- Install the bolt, nut and retaining pin completely
- Keep the shackle aligned with the intended direction of mechanical loading
- Avoid unintended side loading, twisting or contact with sharp edges
- Replace fittings showing deformation, cracks, severe corrosion or damaged threads
- Follow the approved line-hardware assembly drawing and utility procedure
Frequently Asked Questions
What is the difference between U-type and UL-type shackles?
The letter “L” identifies the extended version. A UL-type shackle has a longer body than a corresponding standard U-type shackle and is used where additional assembly length or clearance is required.
Does “UL” mean that the product is UL Solutions certified?
No. In this product designation, “UL” is the Chinese power-fitting model code for an extended U-type shackle. It must not be presented as an Underwriters Laboratories certification unless a valid UL certificate exists.
Is 70kN the working load limit?
No. The 70kN value is the nominal failure or ultimate mechanical load used for the fitting classification. It must not be presented as a lifting working load limit.
Can this shackle be used for lifting or rigging?
This product is designed as an overhead-line link fitting. It must not be sold or used as a lifting shackle unless it has been separately designed, marked, tested and certified for lifting applications.
How should the correct UL shackle be selected?
Selection must consider the required mechanical load, pin diameter, internal width, overall length, mating hardware and the approved line-assembly drawing.
