Cargo Chain Strength & Grades: A Comprehensive Guide for Flatbed Haulers

Choosing the right tie-down chains for cargo can be a daunting task, especially for new flatbed haulers. The vast range of chain grades and regulations involved can lead to confusion. However, understanding the different chain grades, ratings, and strength is crucial for securing cargo properly and ensuring safety while avoiding costly fines. This guide will break down the cargo chain grades, explain what they mean, and offer insight into how to select the right chains for your job.

Common Mistakes in Cargo Chain Selection

Many flatbed haulers make common mistakes when selecting and using chains. These errors can lead to equipment failure, potential damage, and safety risks. Two major problems often arise:

1. Using hoist load chains for lifting Hoist load chains and cargo chains serve different purposes. Hoist load chains are designed for hoisting equipment but aren’t built to handle the stress of overhead lifting or heavy-duty towing. They don't meet the hardness or strength requirements that chains like Grade 80 or Grade 100 offer. Misusing a hoist load chain in a lifting application can lead to deformation or breakage, which can cause accidents and damage.
2. Misusing or abusing alloy chains Alloy chains, particularly Grade 80 and above, are ideal for heavy-duty tasks, but they require proper care. Common issues with alloy chains include improper storage, lack of regular inspections, and using them beyond their working load limit (WLL). Overloading chains or using them without frequent checks can result in chain failure, posing a significant risk during transport or lifting.

What Is Chain Grade and How Is It Determined?

Chain grade refers to the strength of a chain and is defined by its tensile strength — the maximum stress it can endure before breaking. The higher the grade, the stronger the chain. Understanding how to calculate and interpret chain grades will help you choose the appropriate chains for your tasks.

The tensile strength of a chain is measured in Newtons per square millimeter. For example, a Grade 70 chain can endure 700 Newtons per square millimeter before it begins to bend or break. As the grade number increases, so does the tensile strength and the chain’s ability to handle heavier loads.

The formula used to calculate chain grade is as follows:

• Chain Grade = Maximum Tensile Force (Newtons)/Link Cross-Sectional Area (mm2)

This equation applies to most chain grades and provides insight into the strength of different chains. It’s important to note that chains made from different materials (e.g., carbon steel vs. alloy steel) will behave differently under stress.

Breaking Down Chain Grades: Understanding the Differences

There are multiple grades of chains, each suited for specific applications. Here’s a breakdown of common cargo chain grades and their ideal uses:

Grade 30 Chains These chains are constructed from carbon steel and are designed for lighter-duty applications. They are best for general-purpose use, such as securing light construction materials or agricultural goods. The working load limit for Grade 30 chains ranges from 1,300 to 6,900 lbs, depending on the link size. Though not as strong as higher-grade alloy chains, they are economical and effective for lighter tasks.

Grade 43 Chains Stronger than Grade 30, Grade 43 chains are ideal for jobs like logging, farming, and towing. They offer a working load limit between 2,600 to 13,000 lbs but are not suitable for overhead lifting. They are durable and offer more strength for medium-duty tasks.

Grade 70 Chains Grade 70 chains are among the most commonly used in flatbed hauling, primarily because they strike the perfect balance between strength and cost. With a working load limit ranging from 3,150 to 15,800 lbs, these chains are perfect for heavy load tie-downs and tough towing jobs. The yellow chrome finish on these chains offers corrosion resistance and ensures compliance with DOT regulations. Grade 70 is popular for both truckers and loggers.

Grade 80 Chains Grade 80 chains are made from alloy steel and are built for heavy-duty lifting and towing. These chains are suitable for overhead lifting and rigging applications, offering a higher tensile strength than carbon steel chains. They have a working load limit of 3,500 to 18,100 lbs and are typically black-coated for durability.

Grade 100 Chains Offering 25% more strength than Grade 80, Grade 100 chains are some of the strongest chains available. These chains are made from high-quality alloy steel and are suitable for the most demanding tasks, including overhead lifting, construction, and manufacturing. With a working load limit ranging from 4,300 to 22,600 lbs, they’re perfect for extremely heavy-duty lifting and towing jobs.

Grade 120 Chains Grade 120 chains are the strongest in the industry, offering 50% more strength than Grade 80 and 20% more than Grade 100. These chains are specifically designed for the toughest jobs and are easily identifiable by their blue coating and rectangular links. Grade 120 chains are rated for working load limits between 5,200 and 27,500 lbs, making them suitable for specialized lifting and towing operations.

Understanding Working Load Limits (WLL)

Each chain grade has a Working Load Limit (WLL), which is the maximum weight a chain can safely handle. It’s crucial to ensure that the chain you select can handle the weight of the cargo being secured or lifted. The WLL is calculated by dividing the Minimum Breaking Load (MBL) by a Safety Factor (SF). This ratio ensures that the chain can handle stress beyond the actual load, accounting for external forces like angles and gravity.

For example, you should never use a chain that has a WLL lower than the weight of the load being secured. It’s always better to choose a chain with a higher WLL to ensure safety and durability.

Key Factors to Consider When Choosing Chains

When selecting chains for cargo securement, consider the following key factors:

• Weight and Type of Cargo Always choose a chain grade based on the weight and nature of the load. For heavier cargo, consider stronger chains like Grade 80 or 100. The type of cargo also determines the required strength of the chain, as materials like construction supplies or machinery may require more durable chains than lighter, non-industrial goods.
• Regulatory Requirements Be aware of regulations set by organizations like the Department of Transportation (DOT) and the Commercial Vehicle Safety Alliance (CVSA). Compliance with these standards is crucial for legal and safety reasons. Failing to meet DOT and CVSA requirements could result in fines or accidents.
• Environmental Conditions Environmental factors like weather and corrosion can impact the performance of your chains. For outdoor applications, ensure that the chains are made from corrosion-resistant materials or coated to protect against the elements.
• Inspection and Maintenance Regular inspections of chains are critical to ensure they remain in good working condition. Check for any signs of wear, cracks, or deformation. Storing chains properly and maintaining them by cleaning and lubricating them will increase their lifespan and prevent unexpected failures.

Conclusion: Choosing the Right Chain for the Job

Understanding cargo chain strength and grades is essential for flatbed haulers. By choosing the correct chain grade, adhering to load limits, and following safety regulations, you can avoid accidents, prevent cargo damage, and ensure smooth operations. Regularly inspect chains for signs of wear and tear, and always ensure you are using the correct chain grade for your load.

Selecting the right chain is about more than just strength — it’s about safety, compliance, and protecting both your cargo and your business. Take the time to familiarize yourself with chain grades, working load limits, and safety standards to ensure your cargo securement practices are top notch.

This article was first published on myteeproducts.com. Read here: Chain Grades Chart: Cargo Chain Strength and Grades Guide for Flatbedder