Chain Grades: Comparing Grade 30, Grade 43, Grade 70, Grade 80, Grade 100, and Grade 120 Chain

We turned one our most popular posts, “What are the Differences Between Grade 70 Chain, Grade 80 Chain, Grade 100 Chain, and Grade 120 Chain?”, into a simple chart for quick and easy chain grade comparison.

We also added information on the Grade 30 chain and Grade 43 chain. While we don’t sell these chain grades on our website, you can always call in to order them.

chain grade information

Typical Chain Uses

Grade 30

General purpose economical chain. Used in a variety of industries and jobs including light construction, agricultural applications, and the marine industry.

Grade 43

Typically used for container securement, logging, farming, towing, marine applications, and as general purpose utility chain.

Grade 70

Made from a higher strength, heat-treated carbon steel that has a load rating approximately 20 percent higher than Grade 43. The gold chromate finish makes it easy for DOT officials to recognize. Typically used by truckers, loggers, and highway crews for load securement and towing.

Grade 80

A high strength, heat treated alloy chain that can be used as a sling component for overhead lifting as well as heavy duty tow chain. The most economical choice that is suitable for overhead lifting.

Grade 100

A high strength, heat treated alloy chain. Primarily used as a sling component for overhead lifting.  Has approximately 25 percent higher strength than Grade 80. Popular in construction, manufacturing, and rigging applications.

Grade 120

An ultra-premium high strength chain designed specifically for the rigorous requirements of overhead lifting applications. The links have a unique square shape and it has approximately 50 percent higher strength compared to Grade 80. There are currently no official standards for Grade 120 chain in the U.S. or Europe, however, it does meet or exceed the standards of Grade 100 chain.

chain working load limits

Safety Standards for Chain

Organizations like ASTM (American Society of Testing & Materials), ASME (American Society of Mechanical Engineers), and OSHA (Occupational Safety & Health Administration) have released safety standards and regulations for various materials and grades of a chain.  

Essentially, it’s a formal way of recognizing and documenting that not all chain is created equally and therefore, it should not all be used for the same applications. 

ASTM Chain Specification 

What does A413, A391, and A973 all mean? Those are simply how the ASTM categorizes and references their specification standards. Each specification outlines the different manufacturing and testing requirements as well as the appropriate performance standards, grades, and applications.  

Determining Chain Grades

Chain grades are a standard method for showing the ultimate breaking strength (tensile strength) of a chain. Grades help determine what sort of applications are appropriate for a given chain. 

Chain grades are determined by calculating newtons per square millimeter, using the formula “N/mm2”.

Where “mm” is the area of the two cross-sections of a single chain link, and “N” is newtons. A newton is approximately 0.224805 lbs. 

So, to determine a chain grade, manufacturers must find the ultimate breaking strength. Then, divide that number by .224805 to determine ultimate breaking strength in newtons. Next, take that number and divide by the total area of two cross-sections of a single link. That number is the chain grade. 

You could reverse this formula to determine ultimate breaking strength if all you know if the chain grade.  

Note: chain grades advertised by manufacturers are one-tenth of the actual mathematical grades. So grade 80 is really 800, and grade 120 is 1,200. 

Determining Chain Working Load Limits

Working load limit (WLL) of a chain is another designated safety measure. WLL is a weight significantly less than the weight that would cause a chain to fail (tensile strength).

WLL = MBL / SF. Where MBL is minimum breaking load and SF is the safety factor.  

A safety factor is the ratio between allowable stress and actual stress. In other words, it’s the ratio between the chain strength and the expected maximum stress.

In lifting and rigging applications, factors such as gravity and the additional force caused by angles must be considered.  

Always adhere to the WLL to ensure a chain does not break or wear quicker than it should.  

What are the Differences Between Grade 70 Chain, Grade 80 Chain, Grade 100 Chain, and Grade 120 Chain?

A common question our sales team hears from customers is “What are the differences between grade 70 chain, grade 80 chain, grade 100 chain, and grade 120 chain?”

Note: to view a complete chain grade comparison chart and WLL chart, see our recent chain grade overview post.

Grade 70 chain

image of grade 70 transport chain / truckers chain from US Cargo Control

Grade 70 chain is transport chain manufactured in heat-treated carbon steel. As the name suggests, it’s used as tie downs on over-the-road trailers so it’s also known as truckers chain. It’s never to be used for overhead lifting. Grade 70 chain generally features a gold chromate finish so it’s easy to recognize and to meet California Highway Patrol and DOT requirements. In addition to transport uses, it’s also commonly used in towing, logging, oil rigs, and safety chain applications.

Grade 70 chain is embossed with 7, 70, or 700.

 

Grade 80 chain

Grade 80 chain is a heat-treated steel chain with a high strength to weight ratio. Its strength makes it safe for overhead lifting and lifting slings. It’s also excellent for uses such as recovery, safety, and towing chains. Grade 80 chain is also becoming more common in the flatbed trucking industry to secure heavy duty industrial loads. Because these types of chains are generally equipped with a specific type of clevis grab hook, Grade 80 tie down chain assemblies are not approved for overhead lifting.

Grade 80 alloy chain is embossed with 8, 80, or 800.

 

Grade 100 chain

Grade 100 chain is a newer product and is becoming increasingly popular as a replacement for grade 80 chain. Considered premium quality by chain manufacturers, it provides about 25% higher work load limits than grade 80 chain and is approved for overhead lifting applications. Due to the added strength of grade 100 chain over grade 80 chain, it’s becoming more widely used to secure flatbed loads since a smaller-sized chain can be used without sacrificing working load limit capacities. However, because these chains are generally equipped with a specific type of clevis grab hook, Grade 100 tie down chain assemblies are not approved for overhead lifting.

Grade 100 alloy chain is embossed with 10, 100, or 1000.

 

Grade 120 chain

Grade 120 chainimage of grade 120 chain from US Cargo Control is also a newer category of high performance chain, offering the highest strength in the industry. The square link style creates increased contact between the bearing surfaces on the links, which reduces pressure on the chain. This translates to work load limits that are 50% higher than grade 80 chain, and 20% higher than grade 100 chain. Chain grade 120 is approved for overhead lifting. It’s important to note that as with Grade 80 tie down chain assemblies and Grade 100 tie down chain assemblies, Grade 120 tie down chain assemblies are also not safe for overhead lifting due to the type of hooks used.

Grade 120 chains have a bright blue finish to make them easily recognizable.

 

 

 

Regardless of the type of chain, all must adhere to standards set by the National Association of Chain Manufacturers (NACM), which include:

• Chain lifted loads should never to be transported or suspended over people.

• All chains should be periodically inspected for cracks, gouges, wear, elongation, nicks, and suitability.

• Excessive temperatures or exposure to chemically active environments such as acids or corrosive liquids or fumes can reduce a chain’s performance.

• If chains are to be used outside the recommended temperature range ( -40 °F to 400 °F), the user should first consult the chain’s manufacturer.

• If the thickness at any location on the link is less than the listed minimum value, all chain 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.

US Cargo Control offers a full line of grade 70 transport chain, grade 80 chain, grade 100 chain, grade 120 chain, as well as chain slings.

Questions? Give our sales team a call at  866-444-9990. They will be happy to help, or place an order for you.