Transport Chain, also known as Grade 70 chain, is a high-strength, heat-treated carbon steel chain specifically designed for cargo securement and tie-down applications in the transportation industry. Often referred to as “trucker’s chain” or “binder chain,” it is widely recognized for its superior strength and durability in ensuring the safety of loads during transit.

Here’s a breakdown of the key characteristics, applications, and limitations of Grade 70 transport chain:

Key Features:

• Material: Manufactured from high-strength carbon steel that undergoes heat treatment (quenching and tempering) to achieve enhanced strength, hardness, and resistance to wear.
• Grade Marking: Typically embossed with “7,” “70,” or “G70” at regular intervals along the chain to clearly identify its grade. Some manufacturers, like Laclede, may imprint “L7” on their Grade 70 chain, this is the logo for all the people to recgnize their goods.
• Construction: Features a welded link construction. It is commonly available in standard link and long link styles, and sometimes short link options to accommodate specific applications, such as use with certain types of ratchet binders.
• Strength: Offers approximately 20% higher strength than Grade 43 High Test chain, providing a higher Working Load Limit (WLL) for the same nominal size. This means it can safely secure heavier loads with a comparable chain size.
• Finish: The most common finish is yellow chromate or gold zinc plating, this color that not only provides easy identification but also offers good corrosion resistance to withstand the harsh environments often encountered in over-the-road transport. Other finishes may also be available.
• Proof Test: All Grade 70 transport chains are 100% proof-tested, typically at twice the Working Load Limit, and are often accompanied by a certificate of testing.
• Design Factor: Generally has a design factor of 4:1 (minimum breaking load to Working Load Limit), providing an extra margin of safety in load securement applications.
• Meets Standards: Grade 70 transport chain typically meets or exceeds the standards set by ASTM A413/A413M and the National Association of Chain Manufacturers (NACM) specifications, and complies with the regulations of the Department of Transportation (DOT) and the Canadian Council of Motor Transport Administrators (CCMTA) for cargo securement.
• Not for Overhead Lifting: This is a critical limitation. Despite its high strength, Grade 70 chain is never to be used for overhead lifting of personnel or heavy loads. Its material and manufacturing process are optimized for tension and securement, not for the specific safety characteristics required for lifting applications.

Common Applications:

Grade 70 transport chain is the preferred choice for load securement in the transportation industry and is widely used for:

• Trucking: Securing various types of heavy equipment, machinery, vehicles, and other cargo on flatbed trailers or other types of trailers.
• Logging: Securing logs for transport (not for lifting logs).
• Heavy Equipment Hauling: Safely securing construction, agricultural, and industrial equipment to transport vehicles.
• Automotive Hauling: Securing vehicles to prevent movement during transport.
• General Cargo Securement: For various industrial and commercial applications requiring high-strength tie-down chains.

Important Limitations:

• Strictly Prohibited for Overhead Lifting: This is the most crucial limitation to emphasize. Under no circumstances should Grade 70 transport chain be used for overhead lifting operations.
• Do Not Exceed the Working Load Limit (WLL): Always adhere to the WLL marked on the chain or specified by the manufacturer.
• Avoid Shock Loads: Sudden impacts or jerking forces can momentarily exceed the chain’s design load, leading to damage or failure.
• Compatibility of Fittings: All connecting hardware used with Grade 70 chain (such as grab hooks, D-rings, ratchet binders) must have a Working Load Limit equal to or greater than that of the chain.
• Regular Inspection: Inspect chains before and after each use for any signs of wear, deformation, cracks, or other damage. Damaged chains should be immediately removed from service.

Sizes and Specifications:

Grade 70 transport chain is available in various sizes and specifications, with common parameters including:

• Nominal Size (Diameter): Typically ranges from 1/4 inch to 1/2 inch and sometimes larger.
• Working Load Limit (WLL): Varies depending on the size, ranging from a few thousand pounds to over 15,000 pounds.
• Minimum Breaking Load: Typically four times the Working Load Limit.
• Weight per Foot: Increases with the chain diameter.
• Link Dimensions (Inside Length and Width): These dimensions vary depending on the chain size and manufacturer.

How It’s Sold:

Grade 70 transport chain is commonly sold:

• By the Foot: Cut to the specific length required by the customer.
• As Pre-made Assemblies: Chain assemblies with various end fittings (such as grab hooks or J-hooks) that are ready for immediate use in cargo securement.
• In Drums or Pails: For bulk purchases.

When selecting Grade 70 transport chain, it is essential to choose the appropriate size and Working Load Limit based on the weight of the load being secured and the requirements of the transportation. Always prioritize safety and strictly adhere to the manufacturer’s guidelines and warnings, especially regarding the prohibition of overhead lifting.