Why Understanding Types of Shackles Matters? —— Shackles are the most essential components in lifting, rigging, towing, and marine operations. They serve as connecting links in various systems, allowing safe and secure attachment of slings, chains, ropes, and other lifting hardware. Whether you’re lifting a heavy load on a construction site, towing a vehicle, or mooring a vessel, choosing the right type of shackle is critical to safety and performance.
In this guide, we’ll break down the types of shackles, their applications, materials, industry standards, and how to select the right one for your specific need. Whether you’re project manager, procurement officer, or field engineer, this resource will help you make informed decisions.
📌 Table of Contents
What Is a Shackle
A shackle is a U‑shaped metal link secured by a pin or bolt across the opening. It serves as a quick, reliable, and reusable connector that joins slings, chains, wire ropes, and other rigging gear.
What is a shackle used for?
- Construction & Lifting: Anchoring hoists, connecting slings, and supporting loads
- Marine & Offshore: Mooring lines, anchor chains, and deck hardware
- Towing & Recovery: Vehicle recovery straps, winch connections
- Industrial & Utility: Rigging telecom towers, maintaining power lines
- Entertainment & Theatrical: Stage rigging, lighting trusses
Choosing the correct type of shackle directly impacts safety and performance. Next, we’ll cover the most common types of shackles for lifting and beyond.
Main Types of Shackles
Bow Shackle (Anchor Shackle)
- Shape: Wide, bow‑shaped body
- Load Capacity: Allows angular or multi‑directional loading
- Common Use: Perfect for lifting slings, multi-leg bridle connections, and complex rigging layouts.
- Long‑tail Keywords: bow shackle vs D shackle, bow shackle for multi‑leg sling
D Shackle (Chain Shackle)
- Shape: Narrow, D‑shaped body
- Load Capacity: Optimized for straight‑line pulls; not suitable for side loading
- Common Use: Ideal for chain connections, tow straps, and single‑point lifts.
Screw Pin Shackle
- Pin Type: Threaded pin that screws into the shackle body
- Advantages: Easy to install and remove
- Note: Not recommended for applications where pin rotation or vibration may loosen the pin.
Bolt Type (Nut and Cotter) Shackle
- Pin Type: Bolt secured with nut and cotter pin
- Advantages: Highest security; pin cannot unscrew accidentally
- Common Use: Permanent or long‑term installations, offshore platforms, and heavy lifts.
Wide Body Shackles
- Pin Type: Screw pin or bolt-type pin, depending on design
- Advantages: Larger bow radius reduces stress on slings; increases sling life; excellent fatigue resistance; ideal for multi-leg slings and synthetic slings
- Common Use: Heavy lifting, offshore rigging, subsea applications, spreader beam connections
Materials Used in Shackles
Selecting the right shackle material affects strength, durability, and application environment:
| Material | Key Features | Strength | Corrosion Resistance | Typical Uses |
| Carbon Steel | Affordable and strong | High | Low (indoors/dry) | General lifting & industrial |
| Alloy Steel | Higher strength, heat-treated | Very High | Moderate | Heavy-duty lifting, construction |
| Stainless Steel | Excellent corrosion resistance | Moderate | High (marine) | Marine shackles, offshore use |
| Galvanized Steel | Coated for rust protection in outdoor use | Moderate-High | Moderate-High | Outdoor cranes, deck applications |
Decoding Shackle Markings: WLL, Size, Standards
- Every lifting shackle must be marked with essential information:
- Manufacturer Identification
- Shackle Size or Pin Diameter (e.g., 3/4″, 20 mm)
- Working Load Limit (WLL) in tons or kilograms
- Standard Compliance (e.g., ASME B30.26, EN 13889)
- When choosing shackles, especially for lifting and rigging, always check for compliance with international safety and quality standards.
- Look for shackles stamped with WLL (Working Load Limit) and manufacturer identification.
How to Choose the Right Shackle for Your Application
When selecting among types of shackles, consider these key factors:
- Load Direction & Type
- Multi‑directional: Choose a bow shackle
- Single‑point: Use a D shackle
- Working Load Limit (WLL)
- Always exceed the expected load
- Factor in dynamic loads (shock, vibration)
- Material & Environment
- Marine use: Stainless steel or galvanized
- Industrial: Alloy steel for heavy lifts
- Pin Security
- Temporary vs permanent: Screw pin for quick jobs; bolt‑type for permanent
- Standards & Certifications
- Verify ASME B30.26, EN 13889, or ISO 2415 compliance
- Budget & Availability
- Balance cost vs lifetime value; corrosion‑resistant shackles command higher prices but lower replacement frequency.
Essential Shackle Safety Guidelines
Proper use and inspection of rigging shackles prevents accidents and equipment failure. Follow these shackle safety guidelines:
- Inspect Before Each Use: Look for wear, deformation, cracks, or corrosion.
- Never Exceed WLL: Overloading is the leading cause of shackle failure.
- Avoid Side Loading on D Shackles: Use bow shackles if side loads are expected.
- Secure Pins: Ensure screw pins are fully seated and bolt‑type pins are cotter‑pinned.
- Store Properly: Keep shackles in a dry environment; apply anti‑corrosion spray if necessary.
- Replace Damaged Parts Immediately: Do not attempt temporary repairs on bent shackles.
Frequently Asked Questions (FAQs)
Q1: What is a shackle used for?
A: A shackle connects slings, chains, and ropes to loads for lifting, towing, or anchoring.
Q2: What are the most common types of shackles?
A: Bow shackles, D shackles, screw pin shackles, and bolt‑type shackles are the most widely used.
Q3: How do I know what size shackle to use?
A: Use a shackle size chart based on the diameter of pins and body and match with sling/hook size and load requirements.
Q4: What material should I pick for marine shackles?
A: Stainless steel or hot-dip galvanized steel for superior corrosion resistance.
Conclusion: Mastering Types of Shackles for Safer Lifting
Understanding the types of shackles and how to choose the right one is vital for safety, efficiency, and longevity in lifting and rigging tasks. From bow shackles to bolt type shackles, each variation serves a specific purpose. Always consider application, material, and certification when making your decision.
If you’re sourcing quality shackles for lifting, marine, or industrial applications, we invite you to browse our full product range — your trusted supplier of rigging and lifting solutions.
