Grade 30 Proof Coil Chain is a general-purpose, low carbon steel chain, is known for in light-duty applications. It’s a common and economical choice for tasks that don’t require high strength.

Characteristics:

• Material: Typically made from low carbon steel. Some stainless steel(like Type 304 and 316) are available for better corrosion resistance.
• Grade Marking: Usually marked with “3,” “30,” or “300” approximately every foot to indicate its grade. Some manufacturers like to emboss their batch number on their Grade 30 chain, to trace the origin of the chain.
• Construction: Features welded links. It has a non-uniform pitch, meaning it’s not suitable for use with windlasses.
• Finishes: Available in various finishes, including:
  • Self-colored (plain steel)
  • Zinc plated (electro-galvanized)
  • Hot-dipped galvanized (for better weather resistance)
  • Other coatings like yellow chromate or powder coating may be available.
• Link Type: Offered in regular link and long link styles. Long link chains are sometimes preferred for applications where more elongation is needed and are considered more resistant to shock loading in extreme weather.
• Proof Tested: Generally 100% proof tested by the manufacturer. Certificates of proof test are often available upon request.
• Design Factor: Typically has a design factor of 4:1 (Minimum Breaking Load to Working Load Limit).

Common Applications:

Grade 30 proof coil chain is widely used for various light-duty pulling and restraining applications, including:

• Tie-downs: Securing equipment or cargo for transport (though Grade 70 transport chain is often preferred for this in trucking).
• Towing: Light-duty towing applications,it is popolar for fishing industry.
• Logging: Securing logs (not for lifting).
• Barrier chains: Creating temporary barriers or guard rails.
• Agricultural uses: Various general farm applications.
• Marine industry: Mooring, stud anchor chain(generall there are U2 U3 different standard, common in some light applications, but higher grades are generally recommended for critical anchoring).
• Construction: Light construction tasks.
• Pipeline installations: Hanging or securing pipes.
• Truck tailgates: Securing or as part of the tailgate mechanism.Generally need all the link are same, like twins or multiple births.

Important Limitations:

• Not for Overhead Lifting: This is the most critical limitation. Grade 30 proof coil chain must never be used for overhead lifting of personnel or loads. For overhead lifting, use alloy steel chain of the appropriate grade.
• Working Load Limit (WLL): Never exceed the published Working Load Limit for the chain.
• Shock Loads: Avoid subjecting the chain to sudden impacts or jerking forces, as this can significantly exceed the WLL.
• Fitting: Ensure any hooks, shackles, or other fitting used with the chain have at least the same WLL as the chain.

Sizes and Specifications:

Grade 30 proof coil chain comes in a range of sizes, with varying:

• Material Diameter: Typically ranges from 1/8″ to 1″ or even larger.
• Working Load Limit (WLL): Varies significantly with size, from a few hundred pounds to over 17,000 lbs for the largest sizes.
• Proof Test Load: Usually double the Working Load Limit.
• Minimum Breaking Load: Typically four times the Working Load Limit.
• Inside Length and Width of Links: These dimensions vary by chain size and whether it’s a regular or long link.
• Weight per Foot: Increases with the diameter of the chain.

How it’s Sold:

Proof coil chain is commonly sold:

• By the foot or meter: Cut to the specific length needed.
• In pails or drums or bags: For larger quantities, according to the requirement of customers.
• In assemblies: With various end fittings like hooks or shackles.

When selecting Grade 30 proof coil chain, always consider the specific application and ensure that the chain’s specifications (size, WLL, finish) are appropriate for the task. Remember its primary use is for general utility and light-duty securing, towing, and similar applications, and never for lifting.