Chain Grades Chart: Cargo Chain Strength and Grades Guide for Flatbedder’s

Choosing the right tie-down equipment for your cargo can be a stressful or confusing process for most new flatbed haulers. When it comes to tie-down chains, there’s a whole new set of rules and regulations you need to follow to avoid being fined for improperly securing your cargo.

What’s likely the most confusing aspect of cargo chains are their grade ratings and what they mean. At Mytee Products, we’ve crafted an ultimate Cargo Chain Grade Guide to help break it down for you! We’ll go into detail about the types of chain grades, chain ratings, and chain strength as well as what it all means for you!

There are a few very common misunderstandings that people make when trying to find and purchase a chain grade for their load tie-down. Knowing these common mistakes will help ensure that you can avoid making them! According to fellow truckers and chain manufacturers, there are two very common problems flatbed haulers encounter in the industry:

1. Using a hoist load chain for lifting.
2. Misusing or abusing alloy chains.

Load chains are constructed differently from alloy chains, which are what chain grades 80+ are crafted from. Load chains are specifically used within the inner workings of a hoist, which means that they don’t meet the same strength requirements nor hardness requirements that you might find with a Grade 80 or Grade 100 chain rating. If you mistakenly try to use a load chain for overhead lifting, you risk deforming if not completely snapping the chain, which can cause damage to the chain, the hoist, and your load! Load chains are not graded or prepped for the stress that overhead lifting can cause on-chain ratings over 80+ or made with alloy steel.

The second most common mistake is the general misuse or abuse of alloy chains. This could include improperly storing the chains, infrequent or absent inspection of the chains for damages or wear and tear, and frequent overloading or improper use of the tow chain rating. Frequent inspections are the best way to ensure all your trucking tools and supplies are safe to use. Poorly stored or non-inspected equipment can increase the chances of injury or damage while you’re on the road. Additionally, you should NEVER try to haul or lift cargo that is heavier than the total working load limit of all your chains. Even if you’re using the best, heavy-duty G100 chain, hauling a load heavier than the set load limit of the chain increases your risk of severely damaging your chains and cargo.

How do you calculate a chain grade?

With several different ratings, you may be wondering: How do you calculate chain grades? A chain grade’s number or rating refers to the maximum stress it can handle per millimeter squared. If you were to make it a mathematical equation, it would look similar to the following:

Chain Grade = Maximum Tensile Force (Newtons)/Link Cross-Sectional Area (millimeters)2

Breaking down tow chain ratings using this equation, you could discover that a G70 chain can endure 700 Newtons per millimeter squared before bending, disfiguring, or breaking. Remember, the higher the grade, the higher the tensile strength is compared to the size of the chain links.

This equation works for nearly every chain on the chain chart until you get to chains that are designed with different materials. Carbon steel chains, like Grade 30, 43, and 70, cannot handle the stress/Newtons required for tasks such as overhead lifting. Meanwhile, alloy steel chains – like Grade 80 and higher – can handle that kind of tensile force and thus are recommended for any heavy-duty lifting.

Grade Types and Uses

Grade 30

As shown in the chain strength chart above, chain grade 30 has the smallest amount of strength on the market. That said, their low-stress limit actually makes them ideal for general-purpose, economical uses. Perfect for light construction, agriculture, or marine and household applications like swing sets or guard railers. Grade 30 chains are composed of malleable, rust-resistant carbon steel and have a working load limit between 1,300 to 6,900 lbs depending on the size of the link. While they may not be as strong as alloy chains, G30 chains are the least expensive option for your light construction or agricultural job.

Grade 43

Chain Grade 43 are more durable and stronger than chain grade 30 ratings, making them perfect for more demanding jobs like logging, farming, towing, or as a general-purpose utility chain in trucking. Though stronger than G30, these tow chain ratings are still not recommended for overhead lifting jobs and have a working load limit of 2,600 to 13,000 lbs.

Grade 70

Grade 70 Chain may be the most common tow chain rating you will find in the flatbed hauling industry. Usually coated in a yellow chrome finish, the G70 chain has a load rating roughly 20% higher than Grade 43 making it the strongest carbon steel chain available! Perfect for tying down heavy loads and for tough towing jobs, their unique gold coating makes them DOT recognizable and provides protection from abrasion which then increases their on-the-road lifespan.

Uncute Grade Chain 70 has a working load limit between 3,150 to 15,800 lbs. They’re typically used by truckers and loggers for load securement and towing jobs, and have thus earned the nicknames of Transport and Trucker chain!

Also Read: Important Tips on Grade 70 Chain Usage

Grade 80

The first chain on our chain number chart to be made of alloy steel chain, Grade 80 chain is the first suitable chain to be used as a sling for overhead lifting and heavy-duty towing. The unique alloy material makes this chain’s strength incredibly high, carrying a working load limit of 3,500 to 18,100 lbs! Additionally, you will often hear this chain be referred to as the Alloy Chain, and it’s recognizable by the sleek, black coat finish.

Grade 100

About 25% stronger than the chain rating 80, the chain Grade 100 is the strongest chain on most chain suppliers’ markets. G100 is made of similar strong, alloy steel and can be used in a variety of jobs and industries including overhead lifting slings, construction, manufacturing, and rigging! Based on the size of the links, G100 chains have working load limits of 4,300 to 22,600 lbs. It’s the absolute best choice for extremely heavy-duty lifting or towing jobs.

Grade 120

Still pretty new to the trucking scene, chain grade 120 is the strongest possible chain you can buy. 50% stronger than Grade 80 and 20% strong than Grade 100, G120 chains are the most distinguishable chain because of its unique design and style – it has a bright, blue-coat finish and rectangular links! Grade 120 chains have a working load limit of 5,200 to 27,500 lbs, and are built to fit the most rigorous job requirements.

Determining Chain Working Load Limits

Other safety measures that were put into place when identifying which chains are appropriate and safe for overhead lifting was determining the working load limit of each chain grade. The working load limit of a chain differs depending on the size of the links, as seen in the chain number chart above. It’s integral that you know the total weight of the cargo you plan to haul or lift before you purchase any chain rating.

The chain’s working load limit does not have to match the weight of the load, it only needs to be able to handle the stress and tension when applied – this is based on the surface that is being moved plus the weight of the load. Similar to when people ask how to identify chain grades, determining the working load limit of chain grades can be determined with a formula!

WLL = Minimum Breaking Load (MBL)/Safety Factor (SF)

The working load limit of a chain is significantly less than the weight that would cause a chain to fail (the tensile strength of a chain). A safety factor is a ratio between allowable stress and actual stress that the chain can withstand – the ratio between the chain strength and the expected maximum stress! When it comes to lifting and securement, factors like gravity and additional force – like sharp angles – should also be considered. It’s better to be safer than sorry, so spending a little more money on extra chains or a higher chain grade to ensure your chain limit isn’t less than your cargo’s weight can make all the difference! No matter what, always adhere to the WLL of a chain to ensure it doesn’t break or wear down fast.

Determining Chain Grades

One of the biggest questions chain manufacturers have to answer is how to identify a chain grade efficiently and quickly. When determining which grade to give a chain, the biggest safety measure implemented was finding the ultimate breaking strength of the chain! Remember, chain grades are determined by calculating the newtons of stress per millimeter squared (N/mm2). So, when determining a chain grade, reliable manufacturers will find the chain’s ultimate breaking strength and divide the number by .224805 to then find the chain grade.

Safety Standards for Chains

Regardless of the material a chain is made of or the strength it is determined to handle, all chain ratings must adhere to the NACAM (National Association of Chain Manufacturers) safety standards:

• Chain lifted loads should never be transported or suspended over people.
• All chains should be periodically inspected for cracks, wear, disfigurement, nicks, or overall damage.
• Excessive temperatures or chemical exposure can reduce a chain’s performance; avoid these scenarios or frequently check and replace chains when necessary.
• If the thickness at any location of a link is less than the listed minimum value, all chains should be removed from service.
• When mixing chain or component types, all should be rated at the working load limit of the lowest-rated component or chain.

While these aren’t all the standards required for chain manufacturers to meet, they are some of the most important. Should a manufacturer fail to meet these standards, there is a good chance their chains will fail on the road – and failure on the road can lead to injury, cargo damage, or worse! Always make sure you are purchasing the best chains from the best, most reliable manufacturers.

OSHA and ASTM Standards

Once you’ve found the set of chains best suited for your hauling jobs, it is up to you to ensure you are following the OSHA and ASTM Standards for Chain Grades as well. One very important rule you will continue to hear repeated is that overhead lifting should only be administered with the proper type and proper amount of alloy chain slings – never try to lift or haul cargo that exceeds the weight of your combined alloy steel chain strength.

It’s also important to follow all ASME B30 specifications which regard proper components – such as hooks, coupling links, and other rigging equipment – and outlines several approved sling tools. Selecting the proper chain and rigging configuration to get the job done can be challenging and a bit overwhelming, so always address a chain rigging supplier to ensure that you are following all current OSHA and ASTM guidelines.

While there is a massive variety of chain grades on the market and important differences in chain strengths, materials, and uses, we hope that this article will help you navigate the world of cargo chain ratings. Safety standards for tow chain ratings are constantly changing and evolving, so having a good amount of knowledge regarding chain grades and their working load limits allows you to make an informed decision and purchase when choosing the right chains for your cargo.

Use the strongest and most durable lifting chain out there with our high-quality chain slings. These lifting slings provide safe use for any of the toughest overhead lifting and rigging tasks on a regular or repetitive basis. Read on about our sling products and how to choose the right one for you.

Table of Contents:

What are Chain Slings?

Chain slings are the ideal lifting and rigging tool to raise heavy, odd-shaped, and hot materials that other slings could not normally withstand. Our slings consist of an alloy steel chain connected to a master oblong chain link that can easily hook onto any crane, hoist, or jib. The slings also come with a hook end fitting suitable to your specific lifting needs. Besides hooks, other features may differ depending on the brand and make of the chain sling. 

Benefits of Slings

Chain slings offer a wide variety of benefits and uses that other types of slings, like slings or slings, would not normally be able to do.

• Strength & Durability:

  Chain slings and lifting slings work best when you need extra strength and durability. Our hoisting chains include alloy steel that’s Grade 100 or higher, providing approximately 25% higher strength than Grade 80 chains, the industry grade for chain slings.
  
  

• High Temperature Tolerance:

  Our slings can maintain their strength under extremely high temperatures where other slings could not. For example, they can withstand higher working temperatures up to 400 degrees Fahrenheit.
  
  

• Cut-Resistant:

  These lifting chains can easily resist abrasions and withstand other damage that other types of slings could not.
  
  

• Versatility:

  Our chain slings are strong enough to handle a wide variety of lifting and rigging demands under many different conditions.
  
  

• Safer Lifting:

  Our chain links have undergone individual proof testing to ensure its working load limit. The exceptional strength of these rigging chains meets the U.S. standards of ANSI, NACM, ASTM, and OSHA and are safe for overhead lifting jobs.

How to Choose a Sling

At USCC, we have many different chain sling options that tailor to your preferred specifications and needs. There are many factors to consider when choosing the right chain sling such as make or brand, chain sling style, chain length, chain diameter, leg options, and hook end fittings. These factors are configured in a number of ways to provide the variety of chain sling options we have.

1. Choose Your Brand

U.S. Cargo Control offers two trusted brands that sell Grade 100 chain slings or chain sling components, as well as one brand that sells Grade 120 components:

• Crosby

  Crosby has been a leader in the rigging and lifting industry for years, providing some of the highest-quality chain and rigging hardware, including the Crosby Eliminator® hook. Their slings are manufactured in the U.S. and are expertly assembled by our team members at our warehouse. We offer many different options for our Crosby slings that cater to your demands.
  
  

• KWB

  Another manufacturer we carry is KWB, based in Europe. We import their manufactured chain and end fittings and assemble them in the U.S. to provide high-quality slings. KWB slings include Grade 100 alloy steel and have a signal violet varnish coat and a heavy powder coating that helps with corrosion resistance. Similarly to Crosby, our KWB slings come in a variety of options that differ by chain length, end fitting, leg option, and more.
  
  

• Pewag (Grade 120 Chains)

  Pewag is the parent company of KWB and manufactures their sling components and end fittings in Europe. These are imported and expertly assembled by our team to create high-quality, durable slings. Pewag makes Grade 120 chain that allows for a higher working load limit in a lighter sling. They are also made with a light blue powder coating for superior corrosion protection.
  
  

2. Choose Your Style

U.S. Cargo Control offers two different chain sling styles on all our sling brands:

• Standard
  

  Standard slings have a fixed chain length sold in a variety of leg options, chain link widths, diameters, and end fittings.
  
  

• Adjustable

  Adjustable chain slings look very similar to standard slings. However, they feature additional shortener components attached to the master link. These allow you to adjust the length of the chain legs as needed without compromising lifting strength and working load limit.
  
  Crosby and KWB offer adjustable slings and have different adjustment components:
• Crosby Eliminator®
• KWB Grab Hooks

3. Choose Your Leg Option

There are four chain sling leg options to choose from:

• Single-Leg

  Single-Leg chains are extremely versatile since they can be used for load securing and pulling. These slings should be used with vertical hitches and have a 90 degree angle when in use.
  
  

• Double-Leg

  Our two-leg slings are ideal to maintain balanced while lifting materials. These slings are used at a 60, 45, or 30-degree angle of lift. Chain capacity will vary by angle of the lift and by chain size.
  
  

• Triple-Leg

  Similarly to above, the triple-leg sling keeps balance and also uses the same hitch degrees as the double-leg sling.
  
  

• Quad-Leg

  Also known as a 4-leg chain sling or a 4-leg bridle sling, the quad-leg offers the maximum number of chain lengths available on one chain sling assembly. These use the same 60, 45, and 30-degree lift angles as the triple- and double-leg slings.
  
  

4. Choose Your Chain Length

U.S. Cargo Control offers different chain lengths for both our standard and adjustable slings. A chain sling’s length measures from the load-bearing point on the sling’s master link to the load-bearing point on the opposite end when pulled taut.

Our standard slings will have more length options to choose from compared to our adjustable slings. Lengths range from 3’ to 20’ long.

Adjustable slings have four length options to choose from, regardless of which brand you buy: 5 feet, 10 feet, 15 feet, and 20 feet. These chains adjust to whichever length you need using the shortening components.

5. Choose Your Chain Diameter

Our chains come with different thickness measurements, or diameters. The thicker the diameter of the chain link is, the stronger the sling and the higher the working load limit will be. We offer the following diameters:

• 9/32”
• 5/16”
• 3/8”
• 1/2”
• 5/8”
• 3/4"

NOTE: Not every sling will have every diameter offered.

You’ll want to keep an eye out for chain wear the more you use slings. Even with proper care, chains will eventually begin to wear over time. Make sure you regularly inspect the links for minimum allowable thickness. Once it’s worn below this measurement, you should no longer use the chain.

Our table guide below will help you determine what chain wear you should look for in these chains:

6. Choose Your Hook

You can choose which end fitting works best for you. We offer four kinds of end fittings used for different purposes:

• (A) Sling Hook

  These large throat hooks are typically self-locking to avoid disconnecting.
  
  

• (B) Grab Hook

  These have a small throat that attaches to the chain by slinging over the chain in-between links.
  
  

• (C) Foundry Hook

  These are extra-large throat hooks used in unique situations that require a larger opening to manage loads.
  
  

• (D) Self-Locking Hook

  These hooks pivot in the middle and lock under lifting pressure. They cannot be opened while lifted with your overhead lifting chains.
  
  

• (E) Oblong Master Link

  These are generally located at the top of the sling to hook onto the lifting equipment.
  
  

• (F) Adjustable Grab Hook
  

  These hooks attach to a chain link that is attached to the master link toward the top. They are found on KWB slings and help to adjust your chain to whatever length you need.
  
  

Safety Tips for Chain Slings

Here’s what you can do to make sure your chains look good and that you are using them properly:

• Always use slings within posted working load limit
• Distribute loads evenly (an unequal load on one leg can create a dangerous situation and damage the sling)
• Avoid rapid or sudden stops, impacts, and lifts
• Don’t allow a chain leg to be twisted or tied into a knot
• Don’t use slings with damaged, defective, or worn chain
• Protect sharp edges and corners accordingly with padding or protectors to keep chain from coming into contact
• Inspect hooks
• Load hooks should never be tipped or pointed
• Clean chains prior to inspection (oil and dirt can hide chain damage)

It’s always important to follow safety protocols when using these chains for lifting and rigging.

If you have questions over our sling products, get in touch with one of our experts by calling 866-444-9990 or by emailing customerservice@uscargocontrol.com.