Material:

• High-strength alloy steel: This is the most common material for bow shackles due to its excellent strength-to-weight ratio and durability.

• Stainless steel: Used in corrosive environments to prevent rust and corrosion.

Load Capacity:

• Working Load Limit (WLL): The maximum safe load that the shackle can handle.

• Minimum Breaking Load (MBL): The minimum load required to break the shackle. Typically, the MBL is several times the WLL to ensure a safety factor.  

Safety Factor:

• The ratio of the MBL to the WLL. A higher safety factor indicates a more robust shackle.

Finish:

• Hot-dip galvanized: Provides corrosion protection and a longer lifespan.  

• Painted: Offers basic corrosion resistance.

Certification:

• CE marking: Indicates compliance with European Union safety standards.

• ANSI/ASME B30.26: American National Standards Institute and American Society of Mechanical Engineers standards for rigging hardware.  

Additional Considerations:

• Temperature range: Some shackles are designed for specific temperature ranges, especially in extreme conditions.  

• Environmental factors: Consider factors like corrosion, UV radiation, and chemical exposure when selecting a shackle.

• Inspection and maintenance: Regular inspections are crucial to ensure the safety and reliability of bow shackles.