To identify the grade of a welded steel chain, first check several links for a permanent grade mark and manufacturer identification. Match the marks and any trace code to the manufacturer’s product records. If it is a chain sling, also read the identification tag for the assembly’s rated capacity.
Color and diameter alone cannot establish the grade. If the chain or sling cannot be identified and rated for the intended lift, keep it out of lifting service until its identity is verified.
What Does a Chain Grade Number Mean?
Grades 30, 43, 70, 80, and 100 name strength classes of welded steel chain under an applicable specification; they are not tonnage ratings. The NACM welded steel chain specifications calculate grade from nominal stress at the minimum breaking force and the link’s cross-sectional area. A link marked “80” does not mean an 80-ton working load.
A grade mark alone also cannot give you a sling’s capacity. Its rating depends on chain size, the assembled components, and the way the sling is used. A hook or other attachment may set the limit.
Keep the load figures separate: working load limit (WLL) or rated capacity governs use in the stated configuration; proof load is a specified test load; and minimum breaking force is a strength requirement established by testing. Neither proof load nor breaking force is a working rating. For a sling, use the manufacturer’s rating for its legs, hitch, and angle. See OSHA’s alloy steel chain sling guidance.
How to Identify Chain Grade Step by Step?
1. Find the grade marks. Inspect several clean, unloaded links in good light, including both sides where practical. Marks may appear at intervals, so one unmarked link does not settle the question.
2. Find the manufacturer mark and trace code. Read the marks together rather than interpreting an isolated numeral. NACM specifies grade and manufacturer identification, plus traceability or date marking, at prescribed intervals for its Grade 80 and Grade 100 chain. Other specifications may use different layouts.
3. Check the product records. Compare the observed marks, nominal size, and applicable standard with the manufacturer’s specification and available purchase or certificate records. If the markings do not match, ask the supplier to resolve the discrepancy.
4. Check the sling tag if present. The link marks help identify the chain; the tag identifies the rated sling assembly. Check its components and the rated capacity for the intended configuration. A grade mark on one link cannot establish a two-leg sling’s capacity at a given angle.
5. Set aside unresolved lifting gear. If the tag, link, and records conflict or the required identification is missing, do not choose the highest apparent rating. Keep the gear out of lifting service until its identity and rating are established.
Common Chain Grades and Markings
The table shows grade indicators in the U.S. NACM welded steel chain specifications. Read them in the context of the applicable specification and manufacturer marks; they are not a universal code for every chain.
| Grade | NACM indicator examples | Common product context |
| 30 | 3 / 30 / 300 | Proof coil / general utility; check actual product rating. |
| 43 | 4 / 43 / 430 | Transport/cargo securement; not overhead lifting chain. |
| 70 | 7 / 70 / 700 | Transport / cargo securement; not overhead lifting chain. |
| 80 | 8 / 80 / 800 | Alloy chain used in rated lifting assemblies when specified and assembled for that use. |
| 100 | 10 / 100 / 1000 | Higher-grade alloy chain used in rated lifting assemblies when specified and assembled for that use. |
Some smaller Grade 30 and 43 sizes have optional marks under NACM. For Grades 70, 80, and 100, that specification sets marking requirements and intervals. Check the product’s applicable standard before treating an absent mark as proof of a particular grade.
How to Identify Grade 80 and Grade 100 Chain
Grade 80
The example photo shows “G80” on a link. In the NACM specification, 8, 80, and 800 are Grade 80 indicators. The photographed mark is a clue to investigate, not a WLL: check the other markings and the product documentation before using the chain for lifting. Do not expect every Grade 80 chain to say “G80.”
Powerful Machinery’s catalogue lists Grade 80 lifting chain to EN 818-2 and U.S. style alloy chain series. For a specific order, compare the supplied chain’s marks with its product specification and documents.
Grade 100
Under NACM, 10, 100 and 1000 indicate Grade 100. The marking format may differ under another specification. Check the maker and trace marks against the documents for that chain; do not infer its rating from a blue finish.
Powerful Machinery also lists a G100 short-link lifting chain. Use the product sheet and relevant certificate to verify a supplied batch, rather than applying a catalogue rating to an unidentified chain.
How to Read an Alloy Steel Chain Sling Tag?
A sling’s tag identifies the assembly, including information that a chain-link stamp cannot provide. In U.S. general industry, OSHA 29 CFR 1910.184(e)(1) calls for a durable, permanently affixed identification stating size, grade, rated capacity, and reach. In construction, 29 CFR 1926.251(b)(1) specifies size, grade, rated capacity, and sling manufacturer. Apply the provision relevant to the work.
Check that the tag is legible and belongs to the sling in front of you. Read its rating and the manufacturer’s instructions for the number of legs, hitch, and sling angle. The image below shows a tag near the master link on a two-leg sling; its small lettering cannot be used to verify the pictured assembly’s grade or capacity.
If the tag is missing or illegible, do not calculate a sling rating from a link stamp. OSHA requires legible, affixed sling identification for use. Browse the chain slings range for assembly options, then confirm the exact sling rating and identification for the job.
Can You Identify Chain Grade by Color?
Not reliably. Gold, black, or blue finishes may be familiar in particular product lines, but manufacturers can use different finishes, and coatings can wear or be changed. Color does not establish grade or WLL.
Treat a familiar finish as a clue to check the marks and records, especially when different chains have been stored together.
What If the Chain Marking Is Missing or Unreadable?
Inspect the chain unloaded. Remove dirt and oil without damaging the links or remaining marks, then check several links. Record the legible markings and compare them with a tag, product records, and the manufacturer’s documentation. Ask the supplier if the evidence does not match.
Do not stamp a replacement grade yourself. If the grade or required sling identification remains unresolved, keep the gear out of lifting service and follow the manufacturer’s inspection procedure. Identification does not replace checks for wear, deformation, or defective welds. The separate guide to inspecting load chains covers inspection in more detail.
Chain Grade vs Chain Size
Grade is a strength class; size is a physical dimension, usually given by the nominal diameter of the link stock. Chains of the same size can have different grades and ratings. Size helps you locate the correct product specification, but does not prove the grade.
For dimensions, see how to measure chain link size.
Common Chain Grade Identification Mistakes
Reading a grade as tonnage. “G80” is a grade designation; use the stated WLL for the specific chain or assembly.
Assuming an impressive breaking force makes a chain suitable for lifting. Use the manufacturer’s working rating and the product’s intended application.
Using Grade 70 transport chain for overhead lifting. NACM identifies its Grade 70 chain for transport and excludes overhead lifting.
Applying NACM marking conventions to every product. Check the applicable standard and manufacturer’s mark before interpreting a numeral.
FAQs
What Does 8 or 80 Stamped on a Chain Mean?
They are Grade 80 indicator examples under NACM. They do not mean an 8-ton or 80-ton working load.
What Does 10 or 100 Stamped on a Chain Mean?
They are Grade 100 indicator examples under NACM, subject to confirmation with the maker’s marks and documents. They do not state a sling’s capacity.
What Should I Do If a Chain Has No Grade Mark?
Inspect other unloaded links and check the tag and product records. Some smaller utility chain sizes have optional marks under NACM; that does not justify assigning an unidentified chain a lifting rating.
Is Grade 70 Chain Suitable for Overhead Lifting?
No. NACM Grade 70 transport chain is not for overhead lifting. Use a chain and sling assembly rated for the lift.
To identify a chain or specify a replacement sling, send our team clear photos of the link marks and sling tag, the nominal size, intended application, and any available records. For a new assembly, see custom chain sling options and confirm the required rating and documentation before ordering.
