Good question: What is the grade all about?

You will inevitably come across the term “grade" when dealing with lifting-chains and their fittings. But what exactly does the quality class mean?

Eine Tabelle bei der die Tragähigkeiten von Stahlketten verschiedener Güteklassen verglichen wird

Meaning of the grade

For a definition of the grade term, it is worth taking a look at the EN 818-1 standard, which states: “The grade stands for the nominal stress at the specified minimum breaking force of the chain material with the unit [N/mm2].” In technical terms, it therefore describes the ratio of force per load-bearing cross-sectional area. The higher the grade, the higher the load-bearing capacity for the same material thickness. Round steel chains in grade 10, for example, have up to 25% higher load-bearing capacity than chains with a comparable material thickness or weight in grade 8 [see diagram].

Or vice versa: If you want to achieve a load capacity of 10 t with a grade 8 lifting chain, it has a nominal thickness of 18 mm. With a grade 10 lifting chain, you can achieve the same load capacity with a nominal thickness of 16 mm.

The diagram on the left shows a comparison of the load capacities of grade 8 (black), 10 (orange) and 12 (turquoise).

Grades 8, 10 and 12: Products and differences

The proven quality standard for lifting-chains is grade 8. Chains in this grade are high-strength, have a (relatively) low dead weight and high wear resistance. You can also choose from an extensive range of accessories. The Dolezych product range for grade 8 according to DIN EN 818-4 can be found in the steel lifting-chain (Link) category under the name “DoKett”.

“DoKett Plus” and “DoComfort” are the names for our grade 10 lifting-chains, which you can also find in the steel lifting-chains section of the Dolezych store. They are also manufactured in accordance with DIN EN 818-4 and - like chains in the other grades - are certified by the BG. Compared to grade 8 chains, both the “DoKett Plus” and “DoComfort” products offer up to 25% higher load capacity with the same material thickness.

For the same nominal diameter, grade 12 offers a further 20% higher load capacity compared to grade 10 (or even 50% higher than grade 8). This means you benefit from a significant weight saving.

The special cases

The grades 8, 10 and 12 described above are the most common. But beware: Due to the risk of hydrogen embrittlement, they must not be used in some applications, e.g. in pickling plants or hot-dip galvanizing plants. Grade 2 and 4 chains are used in these applications due to their high resistance to acids. Grade 6 stainless steel also offers special areas of application, which is used in the food industry, chemical industry, wet plants, shipping, etc.

Please also note that the performance of the lifting-chains - regardless of the grade - is influenced by the operating temperature.

Labeling with chain pendants

And how can you tell which grade a chain belongs to? The grade must be stamped or embossed on each lifting-chain at regular intervals and clearly legible. According to the standard, “regular spacing” means that the grade must be visible on at least every 20th chain link or at least once per meter (whichever is the smaller spacing). Tags on which the grade is marked are often used to identify lifting-chains. You can recognize our “DoKett” series, for example, by the red, octagonal identification tag.

Lifting-chains by Dolezych.

Textile lifting-chain DoNova^®PowerLift

Lifting sensitive loads gently

Our DoNova^®PowerLift has similar performance features to comparable steel systems. In addition to the sensationally easy handling of the textile lifting-chain, the main focus is on protecting the load and the user's hands. The soft and flexible webbing chain causes no damage or scratches to sensitive loads or delicate surfaces. In addition, you cannot injure yourself on the individual chain links (e.g. by crushing). Thanks to its low dead weight, working with the DoNova^®PowerLift is particularly ergonomic. For asymmetrical loads, the DoNova^®PowerLift can be easily shortened using either high-strength shackles or clevis hooks integrated into the chain.

To the DoNova^®PowerLift

Steel lifting-chains by Dolezych

The steel standard

Lifting-chains are indispensable lifting equipment in industry, enabling loads to be lifted. They serve as a connection between the load-bearing equipment and the payload and can be used in a wide variety of industries. The chains are made of robust round steel. They can be combined with various accessories, such as hooks for lifting-chains (Link). This means you can easily and safely put together the right chain for your specific application. In addition to conventional steel chains, we also offer the alternative option of the innovative DoNova^® textile chain, which has up to 85% less dead weight than a conventional steel chain and therefore enables ergonomic working. You can conveniently buy lifting-chains at the Dolezych store.

To the steel lifting-chains