Industrial chains consist of linked segments of durable metal, such as stainless steel, galvanized steel, and brass. They are available in a wide range of sizes and strengths to lift and transport materials across a diverse set of applications.
The tensile strength of the base material—i.e., the ultimate breaking strength—determines the rating and grade given to the particular chain. The greater the breaking strength, the higher the grade, and vice versa. The grade indicated for a chain helps industry professionals identify the types of applications for which it is appropriate. For example, the strength of galvanized chains relies on the amount of carbon present in the metal; as grade 30 chain has less carbon, it is weaker than grade 40 chain and suitable for service duty applications rather than heavy-duty applications.
At Armstrong / Alar Chain Corporation, we pride ourselves on our extensive knowledge and experience with metal chains, hooks, fasteners, wire rope, and accessories. Our experts understand the uses and limitations of chains and can offer advice on the types and attachments suitable for virtually any application.
Properties of Different Chain Grades
When selecting a chain for an application, it is important to consider its grade. Each chain grade demonstrates different properties that make it suitable for some applications, but not for others. An analysis of the working load limit (WLL) of the chain— generally one-third the weight of the break strength—can help industry professionals determine its strengths and weaknesses. Below we outline some of the most common chain grades and their properties and uses.
Grade 30 Chain
Grade 30 chain is widely used for general purpose use in agricultural, residential, and industrial applications. This grade is composed of durable carbon steel and has the lowest tensile strength of all the chain grades. While it should not be used for heavy-duty towing or overhead lifting, it often finds application as the following:
- Cargo lashing and tie-downs
- Chain guard rails on walking trails
- Crowd control equipment
- Playground equipment components
- Vehicle tow chains for lighter equipment
Grade 40 Chain
Compared to Grade 30 chain, Grade 40 chain has a higher carbon content and therefore exhibits a higher tensile strength. While similar in strength to Grade 43 chain, this grade has smaller chain link dimensions. It is used primarily as boat windlasses but also finds application in mines, oil drilling fields, lumber yards, and OEM facilities. Like Grade 30, this chain is not approved for overhead lifting.
Grade 43 Chain
Grade 43 chain is made from higher carbon steel and demonstrates the same strength levels as grade 40, except with larger chain links. This grade’s higher strength allows it to accommodate DOT specifications for use as tie-downs in the trucking industry. While it cannot be used in overhead lifting applications like Grade 30 and 40, it is appropriate for securing logging loads for on-road transport and vehicle towing.
Grade 70 Chain
Grade 70 chain is composed of heat-treated carbon steel, making it approximately 20% stronger than Grade 43 chains. This grade is easily recognizable by its yellow chromate gold plating finish. It is typically used to secure heavier loads for on-road transport and equally suitable for use in logging and towing, especially for applications that require a chain with greater strength than Grade 43 can offer. Although this chain has significantly higher tensile strength than lower grades, it is not recommended for use in overhead lifting applications.
Grade 80 Chain
Grade 80 chain is fully engineered for safe use in overhead lifting applications and has been approved by the Occupational Safety and Health Administration (OSHA) for this purpose. This grade is composed of heat-treated alloy steel and can be coated with a black armor protective finish to enhance durability and service life. It is designed specifically for use in heavy-duty towing and overhead lifting.
Grade 100 Chain
Like Grade 80 chain, Grade 100 chain has been engineered for exceptional strength and is approved for overhead lifting applications. While the heat-treated alloy steel used in Grade 100 is approximately 25% stronger than Grade 80, there are some reports of decreased tensile strength at low temperatures. The exceptional strength of the base metal allows for the use of smaller diameter chains with a significantly higher strength-to-weight ratio than other alloy chains. Additionally, the material hardness reduces inner wear on the links for longer service life.
Stainless Steel Types 304 and 316 Chain
In addition to carbon steel, manufacturers also employ stainless steel to produce chains with greater corrosion resistance. In particular, they often use 304 and 316 stainless steel grades, which exhibit a higher carbon content than other stainless steel alloys and, therefore, higher tensile strength. The WLLs for stainless steel chains are more dependent on the chain size, with load capacities ranging between 375 pounds to 23,000 pounds.
Applications and Industries Served by Different Chain Grades
Due to their varying material attributes, each chain grade finds use in different applications and industries. For example:
- Grade 30. Grade 30 chain is most commonly used for general purposes. It is a low-cost option for lightweight applications in construction, agriculture, and marine industries.
- Grade 43. The higher strength of Grade 43 accommodates heavier general use, including securing larger and heavier items in the logging, agriculture, automotive towing, and marine industries.
- Grade 70. Approximately 25% stronger than Grade 43, Grade 70 is ideal for securing and towing large or heavy loads for road transport applications in the trucking, logging, and highway construction industries.
- Grade 80. Approved for overhead lifting, Grade 80 chain is often employed for slings and heavy-duty towing in the construction, automotive, aerospace, and manufacturing industries.
- Grade 100. Grade 100 chain is also approved for overhead lifting and used for loads that are heavier and require greater strength than Grade 80 can handle. It is particularly useful for overhead lifting in construction and industrial manufacturing.
- Grade 120. Grade 120 chain exhibits the strongest tensile strength of all steel alloy chains and is used for exceptionally heavy overhead lifting.
Selection Considerations for Different Chain Grades
The key to finding the chain best suited for an application is understanding how the chain will be used, how it is expected to perform, and the factors—such as weight and pressure—acting on it and their effects. These considerations determine the type of chain, including size and strength, that accommodate the requirements and restrictions of the particular application. For example, for overhead lifting, industry professionals may choose to use a Grade 80 or Grade 100 chain but not a Grade 40 or 43 chain. Other concerns to keep in mind are any relevant industry standards and regulations, such as DOT or OSHA requirements.
Superior Chain Products From Armstrong / Alar
At Armstrong / Alar, we understand the need for an intimate understanding of industry standards and regulations. With more than 20 years of experience, we are proud to offer our expertise to help you find the perfect chains, hooks, fasteners, and related accessories to ensure that you have the most secure and reliable chain system. Our highly skilled engineers and specialists are pleased to work one-on-one with your team to help you determine the best system for even the most complex and challenging applications.
Our products are produced from the highest quality materials—including brass, galvanized steel, steel, and stainless steel—and are thoroughly tested for strength and reliability. Our chain product offerings include:
- Welded chains
- Weldless chains
- Beaded chains
- Curb chains